title: Titus Welliver

text: Welliver plays the title role in the TV series "Bosch" from Amazon Studios. The series is based on the novels centered on the character of the same name by Michael Connelly. The first season of the series was released on Amazon Prime Video on February 13, 2015. The series was renewed for a seventh and final season on February 13, 2020. The Bosch series was followed by a May 2022 spin off entitled "" in which Bosch plays a private detective and his daughter, Madeline, (played by ) is a rooky police officer, still set in Los Angeles. Welliver had a cameo appearance as an Imperial captain in the Disney+ series "The Mandalorian".


title: Titus Welliver

text: Welliver is also the narrator of several audiobooks, including Robert B. Parker's series of American western novels, "Appaloosa", "Brimstone", "Blue-Eyed Devil" and "Ironhorse". He has also narrated several of the Michael Connelly "Bosch" series of crime fiction novels, including "The Crossing", "The Burning Room" and "The Wrong Side of Goodbye".


title: Titus Welliver

text: Welliver has been married five times. His marriages to Heather Wielandt, Hollywood talent agent Dani Sexton, and actress Joanna Heimbold ended in divorce. He was widowed when his fourth wife, film producer Elizabeth W. Alexander, died of breast cancer in 2012. He has a daughter with Alexander, and two sons with Heimbold. All three of his children, Cora, Quinn and Eamonn have appeared in Welliver's two series. He married Jose Stemkens, a Dutch fashion consultant and former model, in 2014. Welliver filed for divorce from Stemkens in May 2019. As of May 2022, Welliver is engaged to Samantha Edge.


title: Fat Man

text: "Fat Man" (also known as Mark III) is the codename for the type of nuclear bomb the United States detonated over the Japanese city of Nagasaki on 9 August 1945. It was the second of the only two nuclear weapons ever used in warfare, the first being Little Boy, and its detonation marked the third nuclear explosion in history. It was built by scientists and engineers at Los Alamos Laboratory using plutonium from the Hanford Site, and it was dropped from the Boeing B-29 Superfortress "Bockscar" piloted by Major Charles Sweeney.


title: Fat Man

text: The name Fat Man refers to the early design of the bomb because it had a wide, round shape. Fat Man was an implosion-type nuclear weapon with a solid plutonium core. The first of that type to be detonated was the Gadget in the Trinity nuclear test less than a month earlier on 16 July at the Alamogordo Bombing and Gunnery Range in New Mexico. Two more were detonated during the Operation Crossroads nuclear tests at Bikini Atoll in 1946, and some 120 were produced between 1947 and 1949, when it was superseded by the Mark 4 nuclear bomb. The Fat Man was retired in 1950.


title: Fat Man

text: Robert Oppenheimer held conferences in Chicago in June 1942, prior to the Army taking over wartime atomic research, and in Berkeley, California, in July, at which various engineers and physicists discussed nuclear bomb design issues. They chose a gun-type design in which two sub-critical masses would be brought together by firing a "bullet" into a "target". Richard C. Tolman suggested an implosion-type nuclear weapon, but the proposal attracted little interest.


title: Fat Man

text: The feasibility of a plutonium bomb was questioned in 1942. Wallace Akers, the director of the British "Tube Alloys" project, told James Bryant Conant on 14 November that James Chadwick had "concluded that plutonium might not be a practical fissionable material for weapons because of impurities". Conant consulted Ernest Lawrence and Arthur Compton, who acknowledged that their scientists at Berkeley and Chicago respectively knew about the problem, but they could offer no ready solution. Conant informed Manhattan Project director Brigadier General Leslie R. Groves Jr., who in turn assembled a special committee consisting of Lawrence, Compton, Oppenheimer, and McMillan to examine the issue. The committee concluded that any problems could be overcome simply by requiring higher purity.


title: Fat Man

text: Oppenheimer reviewed his options in early 1943 and gave priority to the gun-type weapon, but he created the E-5 Group at the Los Alamos Laboratory under Seth Neddermeyer to investigate implosion as a hedge against the threat of pre-detonation. Implosion-type bombs were determined to be significantly more efficient in terms of explosive yield per unit mass of fissile material in the bomb, because compressed fissile materials react more rapidly and therefore more completely. Nonetheless, it was decided that the plutonium gun would receive the bulk of the research effort, since it was the project with the least uncertainty involved. It was assumed that the uranium gun-type bomb could be easily adapted from it.


title: Fat Man

text: The gun-type and implosion-type designs were codenamed "Thin Man" and "Fat Man" respectively. These code names were created by Robert Serber, a former student of Oppenheimer's who worked on the Manhattan Project. He chose them based on their design shapes; the Thin Man was a very long device, and the name came from the Dashiell Hammett detective novel "The Thin Man" and series of movies. The Fat Man was round and fat and was named after Sydney Greenstreet's character in Hammett's "The Maltese Falcon". Little Boy came last as a variation of Thin Man.


title: Fat Man

text: Neddermeyer discarded Serber and Tolman's initial concept of implosion as assembling a series of pieces in favor of one in which a hollow sphere was imploded by an explosive shell. He was assisted in this work by Hugh Bradner, Charles Critchfield, and John Streib. L. T. E. Thompson was brought in as a consultant, and discussed the problem with Neddermeyer in June 1943. Thompson was skeptical that an implosion could be made sufficiently symmetric. Oppenheimer arranged for Neddermeyer and Edwin McMillan to visit the National Defense Research Committee's Explosives Research Laboratory near the laboratories of the Bureau of Mines in Bruceton, Pennsylvania (a Pittsburgh suburb), where they spoke to George Kistiakowsky and his team. But Neddermeyer's efforts in July and August at imploding tubes to produce cylinders tended to produce objects that resembled rocks. Neddermeyer was the only person who believed that implosion was practical, and only his enthusiasm kept the project alive.


title: Fat Man

text: Oppenheimer brought John von Neumann to Los Alamos in September 1943 to take a fresh look at implosion. After reviewing Neddermeyer's studies, and discussing the matter with Edward Teller, von Neumann suggested the use of high explosives in shaped charges to implode a sphere, which he showed could not only result in a faster assembly of fissile material than was possible with the gun method, but which could greatly reduce the amount of material required, because of the resulting higher density. The idea that, under such pressures, the plutonium metal itself would be compressed came from Teller, whose knowledge of how dense metals behaved under heavy pressure was influenced by his pre-war theoretical studies of the Earth's core with George Gamow. The prospect of more-efficient nuclear weapons impressed Oppenheimer, Teller, and Hans Bethe, but they decided that an expert on explosives would be required. Kistiakowsky's name was immediately suggested, and Kistiakowsky was brought into the project as a consultant in October 1943.


title: Fat Man

text: The implosion project remained a backup until April 1944, when experiments by Emilio G. Segrè and his P-5 Group at Los Alamos on the newly reactor-produced plutonium from the X-10 Graphite Reactor at Oak Ridge and the B Reactor at the Hanford site showed that it contained impurities in the form of the isotope plutonium-240. This has a far higher spontaneous fission rate and radioactivity than plutonium-239. The cyclotron-produced isotopes, on which the original measurements had been made, held much lower traces of plutonium-240. Its inclusion in reactor-bred plutonium appeared unavoidable. This meant that the spontaneous fission rate of the reactor plutonium was so high that it would be highly likely that it would predetonate and blow itself apart during the initial formation of a critical mass. The distance required to accelerate the plutonium to speeds where predetonation would be less likely would need a gun barrel too long for any existing or planned bomber. The only way to use plutonium in a workable bomb was therefore implosion.


title: Fat Man

text: The impracticability of a gun-type bomb using plutonium was agreed at a meeting in Los Alamos on 17 July 1944. All gun-type work in the Manhattan Project was directed at the Little Boy, enriched-uranium gun design, and the Los Alamos Laboratory was reorganized, with almost all of the research focused on the problems of implosion for the Fat Man bomb. The idea of using shaped charges as three-dimensional explosive lenses came from James L. Tuck, and was developed by von Neumann. A key component needed for the success of the bomb was for there to be absolute precision in all of the plates moving inward at the same time. To overcome the difficulty of synchronizing multiple detonations, Luis Alvarez and Lawrence Johnston invented exploding-bridgewire detonators to replace the less precise primacord detonation system. Robert Christy is credited with doing the calculations that showed how a solid subcritical sphere of plutonium could be compressed to a critical state, greatly simplifying the task, since earlier efforts had attempted the more-difficult compression of a hollow spherical shell. After Christy's report, the solid-plutonium core weapon was referred to as the "Christy Gadget".


title: Fat Man

text: The task of the metallurgists was to determine how to cast plutonium into a sphere. The difficulties became apparent when attempts to measure the density of plutonium gave inconsistent results. At first contamination was believed to be the cause, but it was soon determined that there were multiple allotropes of plutonium. The brittle α phase that exists at room temperature changes to the plastic β phase at higher temperatures. Attention then shifted to the even more malleable δ phase that normally exists in the range. It was found that this was stable at room temperature when alloyed with aluminum, but aluminum emits neutrons when bombarded with alpha particles, which would exacerbate the pre-ignition problem. The metallurgists then hit upon a plutonium–gallium alloy, which stabilized the δ phase and could be hot pressed into the desired spherical shape. As plutonium was found to corrode readily, the sphere was coated with nickel.


title: Fat Man

text: The size of the bomb was constrained by the available aircraft, which were investigated for suitability by Dr. Norman Foster Ramsey. The only Allied aircraft considered capable of carrying the Fat Man without major modification were the British Avro Lancaster and the American Boeing B-29 Superfortress. At the time, the B-29 represented the epitome of bomber technology with significant advantages in Maximum takeoff weight, range, speed, flight ceiling, and survivability. Without the availability of the B-29, dropping the bomb would likely have been impossible. However, this still constrained the bomb to a maximum length of , width of and weight of . Removing the bomb rails allowed a maximum width of .


title: Fat Man

text: Drop tests began in March 1944, and resulted in modifications to the Silverplate aircraft due to the weight of the bomb. High-speed photographs revealed that the tail fins folded under the pressure, resulting in an erratic descent. Various combinations of stabilizer boxes and fins were tested on the Fat Man shape to eliminate its persistent wobble until an arrangement dubbed a "California Parachute", a cubical open-rear tail box outer surface with eight radial fins inside of it, four angled at 45° and four perpendicular to the line of fall holding the outer square-fin box to the bomb's rear end, was approved. In drop tests in early weeks, the Fat Man missed its target by an average of , but this was halved by June as the bombardiers became more proficient with it.


title: Fat Man

text: The early Y-1222 model Fat Man was assembled with some 1,500 bolts. This was superseded by the Y-1291 design in December 1944. This redesign work was substantial, and only the Y-1222 tail design was retained. Later versions included the Y-1560, which had 72 detonators; the Y-1561, which had 32; and the Y-1562, which had 132. There were also the Y-1563 and Y-1564, which were practice bombs with no detonators at all. The final wartime Y-1561 design was assembled with just 90 bolts.


title: Fat Man

text: On 16 July 1945, a Y-1561 model Fat Man, known as the Gadget, was detonated in a test explosion at a remote site in New Mexico, known as the "Trinity" test. It gave a yield of about . Some minor changes were made to the design as a result of the Trinity test. Philip Morrison recalled that "There were some changes of importance... The fundamental thing was, of course, very much the same."


title: Fat Man

text: The plutonium pit was in diameter and contained an "Urchin" modulated neutron initiator that was in diameter. The depleted uranium tamper was an diameter sphere, surrounded by a thick shell of boron-impregnated plastic. The plastic shell had a diameter cylindrical hole running through it, like the hole in a cored apple, in order to allow insertion of the pit as late as possible. The missing tamper cylinder containing the pit could be slipped in through a hole in the surrounding diameter aluminum pusher. The pit was warm to the touch, emitting 2.4 W/kg-Pu, about 15 W for the core.


title: Fat Man

text: The explosion symmetrically compressed the plutonium to twice its normal density before the "Urchin" added free neutrons to initiate a fission chain reaction.


title: Fat Man

text: The result was the fission of about of the of plutonium in the pit, i.e. of about 16% of the fissile material present. The detonation released the energy equivalent to the detonation of . About 30% of the yield came from fission of the uranium tamper.


title: Fat Man

text: The first plutonium core was transported with its polonium-beryllium modulated neutron initiator in the custody of Project Alberta courier Raemer Schreiber in a magnesium field carrying case designed for the purpose by Philip Morrison. Magnesium was chosen because it does not act as a tamper. It left Kirtland Army Air Field on a C-54 transport aircraft of the 509th Composite Group's 320th Troop Carrier Squadron on 26 July and arrived at North Field on Tinian on 28 July. Three Fat Man high-explosive pre-assemblies (designated F31, F32, and F33) were picked up at Kirtland on 28 July by three B-29s: "Luke the Spook" and "Laggin' Dragon" from the 509th Composite Group's 393d Bombardment Squadron, and another from the 216th Army Air Forces Base Unit. The cores were transported to North Field, arriving on 2 August, when F31 was partly disassembled in order to check all its components. F33 was expended near Tinian during a final rehearsal on 8 August. F32 presumably would have been used for a third attack or its rehearsal.


title: Fat Man

text: On 7 August, the day after the bombing of Hiroshima, Rear Admiral William R. Purnell, Commodore William S. Parsons, Tibbets, General Carl Spaatz and Major General Curtis LeMay met on Guam to discuss what should be done next. Since there was no indication of Japan surrendering, they decided to proceed with their orders and drop another bomb. Parsons said that Project Alberta would have it ready by 11 August, but Tibbets pointed to weather reports indicating poor flying conditions on that day due to a storm and asked if the bomb could be made ready by 9 August. Parsons agreed to try to do so.


title: Fat Man

text: Fat Man F31 was assembled on Tinian by Project Alberta personnel, and the physics package was fully assembled and wired. It was placed inside its ellipsoidal aerodynamic bombshell and wheeled out, where it was signed by nearly 60 people, including Purnell, Brigadier General Thomas F. Farrell, and Parsons. It was then wheeled to the bomb bay of the B-29 Superfortress named "Bockscar" after the plane's command pilot Captain Frederick C. Bock, who flew "The Great Artiste" with his crew on the mission. "Bockscar" was flown by Major Charles W. Sweeney and his crew, with Commander Frederick L. Ashworth from Project Alberta as the weaponeer in charge of the bomb.


title: Fat Man

text: "Bockscar" lifted off at 03:47 on the morning of 9 August 1945, with Kokura as the primary target and Nagasaki the secondary target. The weapon was already armed, but with the green electrical safety plugs still engaged. Ashworth changed them to red after ten minutes so that Sweeney could climb to in order to get above storm clouds. During the pre-flight inspection of "Bockscar", the flight engineer notified Sweeney that an inoperative fuel transfer pump made it impossible to use of fuel carried in a reserve tank. This fuel would still have to be carried all the way to Japan and back, consuming still more fuel. Replacing the pump would take hours; moving the Fat Man to another aircraft might take just as long and was dangerous as well, as the bomb was live. Colonel Paul Tibbets and Sweeney therefore elected to have "Bockscar" continue the mission.


title: Fat Man

text: The target for the bomb was the city of Kokura, but it was found to be obscured by clouds and drifting smoke from fires started by a major firebombing raid by 224 B-29s on nearby Yahata the previous day. This covered 70% of the area over Kokura, obscuring the aiming point. Three bomb runs were made over the next 50 minutes, burning fuel and repeatedly exposing the aircraft to the heavy defenses of Yahata, but the bombardier was unable to drop visually. By the time of the third bomb run, Japanese anti-aircraft fire was getting close; Second Lieutenant Jacob Beser was monitoring Japanese communications, and he reported activity on the Japanese fighter direction radio bands.


title: Fat Man

text: Sweeney then proceeded to the alternative target of Nagasaki. It was obscured by clouds, as well, and Ashworth ordered Sweeney to make a radar approach. At the last minute, however, bombardier Captain Kermit K. Beahan found a hole in the clouds. The Fat Man was dropped and exploded at 11:02 local time, following a 43-second free-fall, at an altitude of about . There was poor visibility due to cloud cover and the bomb missed its intended detonation point by almost two miles, so the damage was somewhat less extensive than that in Hiroshima.


title: Fat Man

text: An estimated 35,000–40,000 people were killed outright by the bombing at Nagasaki. A total of 60,000–80,000 fatalities resulted, including from long-term health effects, the strongest of which was leukemia with an attributable risk of 46% for bomb victims. Others died later from related blast and burn injuries, and hundreds more from radiation illnesses from exposure to the bomb's initial radiation. Most of the direct deaths and injuries were among munitions or industrial workers.


title: Fat Man

text: Mitsubishi's industrial production in the city was also severed by the attack; the dockyard would have produced at 80 percent of its full capacity within three to four months, the steelworks would have required a year to get back to substantial production, the electric works would have resumed some production within two months and been back at capacity within six months, and the arms plant would have required 15 months to return to 60 to 70 percent of former capacity. The Mitsubishi-Urakami Ordnance Works, which manufactured the Type 91 torpedoes released in the attack on Pearl Harbor, was destroyed in the blast.


title: Fat Man

text: After the war, two Y-1561 Fat Man bombs were used in the Operation "Crossroads" nuclear tests at Bikini Atoll in the Pacific. The first was known as "Gilda" after Rita Hayworth's character in the 1946 movie "Gilda," and it was dropped by the B-29 "Dave's Dream"; it missed its aim point by . The second bomb was nicknamed "Helen of Bikini" and was placed without its tail fin assembly in a steel caisson made from a submarine's conning tower; it was detonated beneath the landing craft "USS LSM-60". The two weapons yielded about each.


title: Fat Man

text: The Los Alamos Laboratory and the Army Air Forces had already commenced work on improving the design. The North American B-45 Tornado, Convair XB-46, Martin XB-48, and Boeing B-47 Stratojet bombers had bomb bays sized to carry the Grand Slam, which was much longer but not as wide as the Fat Man. The only American bombers that could carry the Fat Man were the B-29 and the Convair B-36. In November 1945, the Army Air Forces asked Los Alamos for 200 Fat Man bombs, but there were only two sets of plutonium cores and high-explosive assemblies at the time. The Army Air Forces wanted improvements to the design to make it easier to manufacture, assemble, handle, transport, and stockpile. The wartime Project W-47 was continued, and drop tests resumed in January 1946.


title: Fat Man

text: The Mark III Mod 0 Fat Man was ordered into production in mid-1946. High explosives were manufactured by the Salt Wells Pilot Plant, which had been established by the Manhattan Project as part of Project Camel, and a new plant was established at the Iowa Army Ammunition Plant. Mechanical components were made or procured by the Rock Island Arsenal; electrical and mechanical components for about 50 bombs were stockpiled at Kirtland Army Air Field by August 1946, but only nine plutonium cores were available. Production of the Mod 0 ended in December 1948, by which time there were still only 53 cores available. It was replaced by improved versions known as Mods 1 and 2 which contained a number of minor changes, the most important of which was that they did not charge the X-Unit firing system's capacitors until released from the aircraft. The Mod 0s were withdrawn from service between March and July 1949, and by October they had all been rebuilt as Mods 1 and 2. Some 120 Mark III Fat Man units were added to the stockpile between 1947 and 1949 when it was superseded by the Mark 4 nuclear bomb. The Mark III Fat Man was retired in 1950.


title: Fat Man

text: A nuclear strike would have been a formidable undertaking in the post-war 1940s due to the limitations of the Mark III Fat Man. The lead-acid batteries which powered the fuzing system remained charged for only 36 hours, after which they needed to be recharged. To do this meant disassembling the bomb, and recharging took 72 hours. The batteries had to be removed in any case after nine days or they corroded. The plutonium core could not be left in for much longer, because its heat damaged the high explosives. Replacing the core also required the bomb to be completely disassembled and reassembled. This required about 40 to 50 men and took between 56 and 72 hours, depending on the skill of the bomb assembly team, and the Armed Forces Special Weapons Project had only three teams in June 1948. The only aircraft capable of carrying the bomb were Silverplate B-29s, and the only group equipped with them was the 509th Bombardment Group at Walker Air Force Base in Roswell, New Mexico. They would first have to fly to Sandia Base to collect the bombs, and then to an overseas base from which a strike could be mounted.


title: Fat Man

text: The Soviet Union's first nuclear weapon was based closely on Fat Man's design thanks to spies Klaus Fuchs, Theodore Hall, and David Greenglass, who provided them with secret information concerning the Manhattan Project and Fat Man. It was detonated on 29 August 1949 as part of Operation "First Lightning".


title: Aaron Donald

text: Aaron Charles Donald (born May 23, 1991) is an American football defensive tackle for the Los Angeles Rams of the National Football League (NFL). He played college football at Pittsburgh, where he received unanimous All-American honors, and was selected by the Rams in the first round of the 2014 NFL Draft. Regarded as one of the greatest defensive players of all time, he has been named Defensive Player of the Year a record three times, along with receiving Pro Bowl selections in all nine of his seasons and seven first-team All-Pro honors. Donald was also a member of the team that won Super Bowl LVI.


title: Aaron Donald

text: A native of Pittsburgh, Donald grew up as one of three children in a working-class family in the city's Lincoln–Lemington–Belmar neighborhood. His father introduced him to workouts, seeking to provide more structure in his son's life. Donald himself would later admit that he was "lazy as a kid." By age 12, he and his father woke up at 4:30 am and worked out for nearly two hours in the basement gym that his father installed in the family home.


title: Aaron Donald

text: Donald attended Penn Hills High School, where he played high school football for head coach Ron Graham. He was selected first-team All-State Class AAAA in each of his final two seasons, and compiled 63 tackles, 15 tackles for loss, and 11 sacks as a senior. Donald also started at offensive guard.


title: Aaron Donald

text: Considered a three-star prospect by "Rivals.com", he was rated as the 37th best defensive tackle in the nation. He committed to hometown Pittsburgh over other scholarship offers from Toledo, Akron, and Rutgers.


title: Aaron Donald

text: As a true freshman, Donald played in all 13 games as a reserve defensive end for Pitt. He recorded 11 tackles, including three for loss, and two sacks. In 2011, as a sophomore, Donald moved into the starting lineup, and turned in a breakout campaign. He recorded 47 tackles, including 16 for loss, 11 sacks and one forced fumble, and was named a second-team All-Big East selection. As a junior, he recorded 64 tackles, including 18.5 for loss, 5.5 sacks, and one forced fumble, earning first-team All-Big East honors. In his senior season, he became one of the most productive defensive players in the entire NCAA. He posted 59 tackles, including a career best 28.5 for loss, 11 sacks, and four forced fumbles. He was named the ACC Defensive Player of the Year and was a unanimous All-American.


title: Aaron Donald

text: At the NFL Combine, Donald set the record for fastest 40-yard dash time for a defensive tackle with a 4.68. The record was previously held by Tank Johnson, who ran a 4.69 in 2004. He drew comparisons to John Randle afterwards. Donald was drafted by the St. Louis Rams in the first round with the 13th overall pick of the 2014 NFL Draft.


title: Aaron Donald

text: On June 16, 2014, the Rams signed Donald to a four-year, fully guaranteed $10.13 million rookie contract. The contract also included a $5.69 million signing bonus and a fifth-year option.


title: Aaron Donald

text: On September 7, 2014, Donald made his regular season debut against the Minnesota Vikings and finished the 34–6 loss with four tackles. The following week, he recorded three tackles and his first NFL sack during a 19–17 victory over the Tampa Bay Buccaneers. On October 13, 2014, he was given his first career start against the San Francisco 49ers and finished the game with four solo tackles. After recording 47 tackles, nine sacks, and two forced fumbles, Donald was one of five rookies selected to the 2015 Pro Bowl. Donald won the NFL Defensive Rookie of the Year award and was named to the NFL All-Rookie Team.


title: Aaron Donald

text: In 2015, Donald began the season as a starting defensive tackle. During the season opener against the Seattle Seahawks, he finished with nine total tackles and two sacks, helping the Rams win 34–31 in overtime. He was named NFC Defensive Player of the Week for the first time in his NFL career for his performance. On December 13, 2015, Donald made five tackles and a career-high three sacks against the Detroit Lions in Week 14. He earned his second NFC Defensive Player of the Week award in 2015 after his performance against the Lions.


title: Aaron Donald

text: Donald started all 16 games, ending the season with 69 tackles, 11 sacks, a pass defended, and a fumble recovery. He earned a First-team All-Pro selection for the first time in his NFL career. He was a Pro Bowl selection for the second consecutive season. He was also ranked 14th by his fellow players on the NFL Top 100 Players of 2016.


title: Aaron Donald

text: On September 12, 2016, Donald was ejected for making illegal contact with a referee in a 28–0 shutout road loss to the San Francisco 49ers on "Monday Night Football". Four days later, he was fined $21,269 for unnecessary roughness ($9,115) and unsportsmanlike conduct ($12,154). During a Week 4 17–13 victory over the Arizona Cardinals, Donald had 1.5 sacks, five total tackles, one tackle-for-loss, five quarterback hits, and a forced fumble. He earned NFC Defensive Player of the Week for the third time in his career after his performance against the Cardinals. On October 21, 2016, he was fined $18,231 for an unsportsmanlike conduct after committing the penalty during a game against the Detroit Lions. Donald was named to his third straight Pro Bowl and his second First-team All-Pro. Donald was also ranked 15th on the NFL Top 100 Players of 2017.


title: Aaron Donald

text: On April 12, 2017, the Rams exercised the fifth-year option on Donald's contract. He did not report to training camp and preseason due to a contract extension dispute. He accumulated about $1.4 million in fines due to his non-participation, and each game that he missed cost him one game check from his base salary of $1.8 million. On September 9, 2017, Donald reported to the Rams and passed his physical, however, he did not play in the season-opener against the Indianapolis Colts the next day, which the Rams won 46-9. Donald made his season debut against the Washington Redskins and recorded two tackles in the 27-20 loss. In the next game against the San Francisco 49ers, he recorded three tackles and sacked Brian Hoyer in the fourth quarter to seal a 41-39 road victory for the Rams. From Weeks 6-9, Donald recorded a sack in each game and had a forced fumble in three of them. During a Week 15 42–7 road victory over the Seattle Seahawks, he recorded five tackles, three sacks, and a forced fumble.


title: Aaron Donald

text: On December 19, 2017, Donald was named to his fourth straight Pro Bowl. He was also later named a first-team All-Pro for the third time. Donald finished the 2017 season with 41 tackles, 11 sacks, and a career-high five forced fumbles. After a stellar 2017 season, Donald was named the NFL Defensive Player of the Year. He was ranked #7 by his peers on the NFL Top 100 Players of 2018.


title: Aaron Donald

text: On August 31, 2018, after holding out all offseason, Donald signed a six-year, $135 million contract extension with $87 million guaranteed. The deal made him the highest paid defensive player in NFL history, until Khalil Mack signed a $141 million contract with the Chicago Bears the next day after being traded from the Oakland Raiders.


title: Aaron Donald

text: During Week 7 against the San Francisco 49ers, Donald finished with four sacks on quarterback C. J. Beathard, along with nine tackles, six for a loss, and five quarterback hits in a 39–10 road victory, earning him NFC Defensive Player of the Week for the fourth time in his career. Donald was named the NFC Defensive Player of the Month for the month of October after recording eight sacks, 17 tackles, and a forced fumble. In Week 16, Donald recorded seven tackles (four for a loss) and three sacks in a 31–9 victory over the Arizona Cardinals, earning him his fifth NFC Defensive Player of the Week. His three sacks brought his season total to 19.5, which broke the record for most sacks in a season by a defensive tackle, previously held by Keith Millard with 18.0. Donald added another sack in Week 17 against the 49ers and finished the season with a league-leading 20.5 sacks. Donald was named NFC Defensive Player of the Month for December, his second such award in the season. Donald was named to the Pro Bowl for his 2018 season.


title: Aaron Donald

text: On January 4, 2019, Donald was named to the AP All-Pro First-team, being the only unanimous selection. On February 2, 2019, Donald was named NFL Defensive Player of the Year for the second consecutive season, joining Lawrence Taylor and J. J. Watt as the only players who have won the award in consecutive seasons. Donald helped the Rams defeat the Dallas Cowboys in the and the New Orleans Saints in the to reach the Super Bowl. In Super Bowl LIII Donald recorded five tackles but the Rams lost by a score of 13–3 to the New England Patriots, with the Patriots offensive linemen (including Joe Thuney) double teaming Donald in order to neutralize his effectiveness which was cited as a key factor in the result. He was ranked as the best player in the NFL by his peers on the NFL Top 100 Players of 2019.


title: Aaron Donald

text: During Week 3 against the Cleveland Browns, Donald recorded his first sack of the season on Baker Mayfield in the 20–13 road victory. However, six days after the game, he was fined $21,056 for a roughing the passer hit on Mayfield. Three weeks later against the San Francisco 49ers, Donald sacked Jimmy Garoppolo twice in the 20–7 loss. In the next game against the Atlanta Falcons, Donald recorded a strip sack on Matt Ryan and recovered the football in the 37–10 road victory. During Week 11 against the Chicago Bears on Sunday Night Football, Donald recorded two sacks, four tackles, and a pass defensed in a 17–7 victory, earning NFC Defensive Player of the Week honors. During Week 16 against the 49ers, he sacked Garoppolo 1.5 times during a 34–31 road loss. Donald was selected for the 2020 Pro Bowl after finishing the 2019 season with 48 tackles, 12.5 sacks, two pass deflections, two forced fumbles, and a fumble recovery in 16 games and starts. He earned First Team All-Pro honors. He was ranked third by his fellow players on the NFL Top 100 Players of 2020.


title: Aaron Donald

text: In the season-opener against the Dallas Cowboys on "Sunday Night Football" Donald recorded his first sack of the season on Dak Prescott during the 20–17 win. Two weeks later against the Buffalo Bills, he recorded two sacks on Josh Allen, one of which was a strip sack that he later recovered during the 35–32 road loss. During Week 5 against the Washington Football Team Donald recorded four sacks during the 30–10 road victory. He was named the NFC Defensive Player of the Week for his performance. Three weeks later against the Miami Dolphins Donald recorded a strip sack on rookie quarterback Tua Tagovailoa on Tagovailoa's first career passing attempt during the 28–17 road loss. In Week 12 against the San Francisco 49ers Donald recorded a sack on Nick Mullens and forced a fumble on running back Raheem Mostert that was recovered and returned by teammate Troy Hill for a touchdown during the 23–20 loss.


title: Aaron Donald

text: Donald was selected for the 2021 Pro Bowl. He earned First Team All-Pro honors. In the of the playoffs against the Seattle Seahawks, Donald sacked Russell Wilson twice during the 30–20 win. On February 6, 2021, Donald was named 2020 NFL Defensive Player of the Year for the third time in four years. He was ranked second by his fellow players on the NFL Top 100 Players of 2021.


title: Aaron Donald

text: In Week 12 against the Green Bay Packers, Donald choked offensive lineman Lucas Patrick. He was fined $10,300 for his behavior. Two weeks later, Donald had three sacks, five tackles, three for a loss, and a pass deflection in a 30–23 road victory over the Arizona Cardinals, earning NFC Defensive Player of the Week. He earned NFC Defensive Player of the Month for December. Donald earned a Pro Bowl nomination and First Team All-Pro honors. Similar to what happened in Week 12, Donald choked D. J. Humphries in the against the Cardinals and threw a punch. The Rams won the game 34–11 to advance to the , where they defeated the Tampa Bay Buccaneers 30–27.


title: Aaron Donald

text: In the , his pressure of 49ers quarterback Jimmy Garoppolo led to a game-sealing interception as the Rams won their second NFC Championship in four seasons, by a score of 20–17. In Super Bowl LVI against the Cincinnati Bengals, Donald had two sacks and three quarterback hits, including the game-sealing pressure play on fourth-and-1 with less than a minute remaining that resulted in an incompletion and the 23–20 win. He was ranked second by his fellow players on the NFL Top 100 Players of 2022.


title: Aaron Donald

text: On June 7, 2022, the Rams announced they had re-negotiated Donald's existing contract extension that was signed in 2018. The deal, which added $40 million over the last three years of the original six-year, $135 million deal, makes Donald the first non-quarterback to average more than $30 million per season.


title: Aaron Donald

text: Donald's older brother, Archie Jr., was a star linebacker at Toledo who "bounced around the NFL as an undrafted free agent until retiring in 2012". The brothers, who shared bunk beds in their childhood, frequently thought about one day helping their parents retire, which according to Gonzalez became one of the driving forces in Aaron's career. On April 27, 2020, Donald revealed on Twitter that he had graduated from the University of Pittsburgh with a degree in communications.


title: Aaron Donald

text: In 2021, Donald and his wife had a son. Donald also has two other children, a daughter and a son, from a previous relationship.


title: Betelgeuse

text: Betelgeuse is a red supergiant of spectral type M1-2 and one of the largest stars visible to the naked eye. It is usually the tenth-brightest star in the night sky and, after Rigel, the second-brightest in the constellation of Orion. It is a distinctly reddish, semiregular variable star whose apparent magnitude, varying between +0.0 and +1.6, has the widest range displayed by any first-magnitude star. At near-infrared wavelengths, Betelgeuse is the brightest star in the night sky. Its Bayer designation is α Orionis, Latinised to Alpha Orionis and abbreviated Alpha Ori or α Ori.


title: Betelgeuse

text: If it were at the center of our Solar System, its surface would lie beyond the asteroid belt and it would engulf the orbits of Mercury, Venus, Earth, and Mars. Nevertheless, there are several even larger stars in the Milky Way, including supergiants like Mu Cephei and the peculiar hypergiant, VY Canis Majoris. Calculations of Betelgeuse's mass range from slightly under ten to a little over twenty times that of the Sun. For various reasons, its distance has been quite difficult to measure; current best estimates are on the order of 500–600 light-years from the Suna comparatively wide uncertainty for a relatively nearby star. Its absolute magnitude is about −6. Less than 10 million years old, Betelgeuse has evolved rapidly because of its large mass and is expected to end its evolution with a supernova explosion, most likely within 100,000 years. Having been ejected from its birthplace in the Orion OB1 associationwhich includes the stars in Orion's Beltthis runaway star has been observed to be moving through the interstellar medium at a speed of , creating a bow shock over four light-years wide.


title: Betelgeuse

text: In 1920, Betelgeuse became the first extrasolar star whose photosphere's angular size was measured. Subsequent studies have reported an angular diameter (i.e., apparent size) ranging from 0.042 to 0.056 arcseconds; that range of determinations is ascribed to non-sphericity, limb darkening, pulsations and varying appearance at different wavelengths. It is also surrounded by a complex, asymmetric envelope, roughly 250 times the size of the star, caused by mass loss from the star itself. The Earth-observed angular diameter of Betelgeuse is exceeded only by those of R Doradus and the Sun.


title: Betelgeuse

text: Starting in October 2019, Betelgeuse began to dim noticeably, and by mid-February 2020 its brightness had dropped by a factor of approximately 3, from magnitude 0.5 to 1.7. By 22 February 2020, Betelgeuse stopped dimming and started to brighten again; and, as reported on 25 February 2022, has remained in a more normal brightness range. Infrared observations found no significant change in brightness over the last 50 years, suggesting that the dimming was due to a change in extinction or "large-grain circumstellar dust", rather than an underlying change in the luminosity of the star. A 2022 study using the Hubble Space Telescope suggests that occluding dust was created by a surface mass ejection. This surface mass ejection cast material millions of miles from the star that then cooled to form the dust that caused the star's dimming.


title: Betelgeuse

text: The traditional name "Betelgeuse" has been derived from the Arabic "" "the hand of "al-Jauzā’" [i.e. Orion]". An error, in the 13th century AD, reading the Arabic "ya" as "ba" led to the European name. In English, there are four common pronunciations of this name, depending on whether the first "e" is pronounced short or long and whether the "s" is pronounced "s" or "z":


title: Betelgeuse

text: In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN, which included "Betelgeuse" for this star. It is now so entered in the IAU Catalog of Star Names.


title: Betelgeuse

text: Betelgeuse and its red coloration have been noted since antiquity; the classical astronomer Ptolemy described its color as ὑπόκιρρος ("hypókirrhos" = more or less orange-tawny), a term that was later described by a translator of Ulugh Beg's "Zij-i Sultani" as "rubedo", Latin for "ruddiness". In the nineteenth century, before modern systems of stellar classification, Angelo Secchi included Betelgeuse as one of the prototypes for his Class III (orange to red) stars. By contrast, three centuries before Ptolemy, Chinese astronomers observed Betelgeuse as having a "yellow" color; if accurate, such an observation could suggest the star was in a yellow supergiant phase around this time, a possibility given current research into the complex circumstellar environment of these stars.


title: Betelgeuse

text: Aboriginal groups in South Australia have shared oral tales of the variable brightness of Betelgeuse for at least 1,000 years.


title: Betelgeuse

text: The variation in Betelgeuse's brightness was described in 1836 by Sir John Herschel, when he published his observations in "Outlines of Astronomy". From 1836 to 1840, he noticed significant changes in magnitude when Betelgeuse outshone Rigel in October 1837 and again in November 1839. A 10 year quiescent period followed; then in 1849, Herschel noted another short cycle of variability, which peaked in 1852. Later observers recorded unusually high maxima with an interval of years, but only small variations from 1957 to 1967. The records of the American Association of Variable Star Observers (AAVSO) show a maximum brightness of 0.2 in 1933 and 1942, and a minimum of 1.2, observed in 1927 and 1941. This variability in brightness may explain why Johann Bayer, with the publication of his "Uranometria" in 1603, designated the star "alpha" as it probably rivaled the usually brighter Rigel ("beta"). From Arctic latitudes, Betelgeuse's red colour and higher location in the sky than Rigel meant the Inuit regarded it as brighter, and one local name was "Ulluriajjuaq" "large star".


title: Betelgeuse

text: In 1920, Albert Michelson and Francis Pease mounted a 6 meter interferometer on the front of the 2.5 meter telescope at Mount Wilson Observatory. Helped by John Anderson, the trio measured the angular diameter of Betelgeuse at 0.047″, a figure which resulted in a diameter of () based on the parallax value of . However, limb darkening and measurement errors resulted in uncertainty about the accuracy of these measurements.


title: Betelgeuse

text: The 1950s and 1960s saw two developments that would affect stellar convection theory in red supergiants: the Stratoscope projects and the 1958 publication of "Structure and Evolution of the Stars", principally the work of Martin Schwarzschild and his colleague at Princeton University, Richard Härm. This book disseminated ideas on how to apply computer technologies to create stellar models, while the Stratoscope projects, by taking balloon-borne telescopes above the Earth's turbulence, produced some of the finest images of solar granules and sunspots ever seen, thus confirming the existence of convection in the solar atmosphere.


title: Betelgeuse

text: In the 1970s, astronomers saw some major advances in astronomical imaging technology, beginning with Antoine Labeyrie's invention of speckle interferometry, a process that significantly reduced the blurring effect caused by astronomical seeing. It increased the optical resolution of ground-based telescopes, allowing for more precise measurements of Betelgeuse's photosphere. With improvements in infrared telescopy atop Mount Wilson, Mount Locke, and Mauna Kea in Hawaii, astrophysicists began peering into the complex circumstellar shells surrounding the supergiant, causing them to suspect the presence of huge gas bubbles resulting from convection. But it was not until the late 1980s and early 1990s, when Betelgeuse became a regular target for aperture masking interferometry, that breakthroughs occurred in visible-light and infrared imaging. Pioneered by John E. Baldwin and colleagues of the Cavendish Astrophysics Group, the new technique employed a small mask with several holes in the telescope pupil plane, converting the aperture into an ad hoc interferometric array. The technique contributed some of the most accurate measurements of Betelgeuse while revealing bright spots on the star's photosphere. These were the first optical and infrared images of a stellar disk other than the Sun, taken first from ground-based interferometers and later from higher-resolution observations of the COAST telescope. The "bright patches" or "hotspots" observed with these instruments appeared to corroborate a theory put forth by Schwarzschild decades earlier of massive convection cells dominating the stellar surface.


title: Betelgeuse

text: In 1995, the Hubble Space Telescope's Faint Object Camera captured an ultraviolet image with a resolution superior to that obtained by ground-based interferometers—the first conventional-telescope image (or "direct-image" in NASA terminology) of the disk of another star. Because ultraviolet light is absorbed by the Earth's atmosphere, observations at these wavelengths are best performed by space telescopes. Like earlier pictures, this image contained a bright patch indicating a region in the southwestern quadrant hotter than the stellar surface. Subsequent ultraviolet spectra taken with the Goddard High Resolution Spectrograph suggested that the hot spot was one of Betelgeuse's poles of rotation. This would give the rotational axis an inclination of about 20° to the direction of Earth, and a position angle from celestial North of about 55°.


title: Betelgeuse

text: In a study published in December 2000, the star's diameter was measured with the Infrared Spatial Interferometer (ISI) at mid-infrared wavelengths producing a limb-darkened estimate of – a figure entirely consistent with Michelson's findings eighty years earlier. At the time of its publication, the estimated parallax from the Hipparcos mission was , yielding an estimated radius for Betelgeuse of . However, an infrared interferometric study published in 2009 announced that the star had shrunk by 15% since 1993 at an increasing rate without a significant diminution in magnitude. Subsequent observations suggest that the apparent contraction may be due to shell activity in the star's extended atmosphere.


title: Betelgeuse

text: In addition to the star's diameter, questions have arisen about the complex dynamics of Betelgeuse's extended atmosphere. The mass that makes up galaxies is recycled as stars are formed and destroyed, and red supergiants are major contributors, yet the process by which mass is lost remains a mystery. With advances in interferometric methodologies, astronomers may be close to resolving this conundrum. In July 2009, images released by the European Southern Observatory, taken by the ground-based Very Large Telescope Interferometer (VLTI), showed a vast plume of gas extending from the star into the surrounding atmosphere. This mass ejection was equal to the distance between the Sun and Neptune and is one of multiple events occurring in Betelgeuse's surrounding atmosphere. Astronomers have identified at least six shells surrounding Betelgeuse. Solving the mystery of mass loss in the late stages of a star's evolution may reveal those factors that precipitate the explosive deaths of these stellar giants.


title: Betelgeuse

text: A pulsating semiregular variable star, Betelgeuse is subject to multiple cycles of increasing and decreasing brightness due to changes in its size and temperature. The astronomers who first noted the dimming of Betelgeuse, Villanova University astronomers Richard Wasatonic and Edward Guinan, and amateur Thomas Calderwood, theorize that a coincidence of a normal 5.9-year light-cycle minimum and a deeper-than-normal 425-day period are the driving factors. Other possible causes hypothesized by late-2019 were an eruption of gas or dust, or fluctuations in the star's surface brightness.


title: Betelgeuse

text: By August 2020, long-term and extensive studies of Betelgeuse, primarily using ultraviolet observations by the Hubble Space Telescope, suggest that the unexpected dimming was probably caused by an immense amount of superhot material ejected into space. The material cooled and formed a dust cloud that blocked the starlight coming from about a quarter of Betelgeuse's surface. Hubble captured signs of dense, heated material moving through the star's atmosphere in September, October, and November before multiple telescopes observing the more marked dimming in December and the first several months of 2020.


title: Betelgeuse

text: By January 2020, Betelgeuse had dimmed by a factor of approximately 2.5 from magnitude 0.5 to 1.5, and reported still fainter in February in "The Astronomer's Telegram" at a record minimum of +1.614, noting that the star is currently the "least luminous and coolest" in the 25 years of their studies and also calculating a decrease in radius. "Astronomy" magazine described it as a "bizarre dimming", and popular speculation inferred that this might indicate an imminent supernova. This dropped Betelgeuse from one of the top 10 brightest stars in the sky to outside the top 20, noticeably dimmer than its near neighbor Aldebaran. Mainstream media reports discussed speculation that Betelgeuse might be about to explode as a supernova, but astronomers note that the supernova is expected to occur within approximately the next 100,000 years and is thus unlikely to be imminent.


title: Betelgeuse

text: By 17 February 2020, Betelgeuse's brightness had remained constant for about 10 days, and the star showed signs of rebrightening. On 22 February 2020, Betelgeuse may have stopped dimming altogether, all but ending the dimming episode. On 24 February 2020, no significant change in the infrared over the last 50 years was detected; this seemed unrelated to the recent visual fading, and suggested that an impending core collapse may be unlikely. Also on 24 February 2020, further studies suggested that occluding "large-grain circumstellar dust" may be the most likely explanation for the dimming of the star. A study that uses observations at submillimetre wavelengths rules out significant contributions from dust absorption. Instead, large starspots appear to be the cause for the dimming. Followup studies, reported on 31 March 2020 in "The Astronomer's Telegram", found a rapid rise in the brightness of Betelgeuse.


title: Betelgeuse

text: Betelgeuse is almost unobservable from the ground between May and August because it is too close to the Sun. Before entering its 2020 conjunction with the Sun, Betelgeuse had reached a brightness of +0.4 . Observations with the STEREO-A spacecraft made in June and July 2020 showed that the star had dimmed by 0.5 since the last ground-based observation in April. This is surprising, because a maximum was expected for August/September 2020, and the next minimum should occur around April 2021. However, Betelgeuse's brightness is known to vary irregularly, making predictions difficult. The fading could indicate that another dimming event might occur much earlier than expected. On 30 August 2020, astronomers reported the detection of a second dust cloud emitted from Betelgeuse, and associated with recent substantial dimming (a secondary minimum on 3 August) in luminosity of the star.


title: Betelgeuse

text: In June 2021, the dust has been explained as possibly caused by a cool patch on its photosphere and in August a second independent group confirmed these results. The dust is thought to have resulted from the cooling of gas ejected from the star. An August 2022 study using the Hubble Space Telescope confirmed previous research and suggested the dust could have been created by a surface mass ejection. It conjectured as well the dimming could came from short-term minimum coinciding with a long-term minimum producing a grand minimum, a 416-day cycle and 2010-day cycle respectively, a mechanism first suggested by astronomer Leo Goldberg.


title: Betelgeuse

text: As a result of its distinctive orange-red color and position within Orion, Betelgeuse is easy to find with the naked eye. It is one of three stars that make up the Winter Triangle asterism, and it marks the center of the Winter Hexagon. At the beginning of January of each year, it can be seen rising in the east just after sunset. Between mid-September to mid-March (best in mid-December), it is visible to virtually every inhabited region of the globe, except in Antarctica at latitudes south of 82°. In May (moderate northern latitudes) or June (southern latitudes), the red supergiant can be seen briefly on the western horizon after sunset, reappearing again a few months later on the eastern horizon before sunrise. In the intermediate period (June–July), it is invisible to the naked eye (visible only with a telescope in daylight), except around midday in Antarctic regions between 70° and 80° south latitude (during polar night, when the Sun is below the horizon).


title: Betelgeuse

text: Betelgeuse is a variable star whose visual magnitude ranges between 0.0 and +1.6 . There are periods during which it surpasses Rigel to become the sixth brightest star, and occasionally it will become even brighter than Capella. At its faintest, Betelgeuse can fall behind Deneb and Beta Crucis, themselves both slightly variable, to be the twentieth-brightest star.


title: Betelgeuse

text: Betelgeuse has a B–V color index of 1.85 – a figure which points to its pronounced "redness". The photosphere has an extended atmosphere, which displays strong lines of emission rather than absorption, a phenomenon that occurs when a star is surrounded by a thick gaseous envelope (rather than ionized). This extended gaseous atmosphere has been observed moving toward and away from Betelgeuse, depending on fluctuations in the photosphere. Betelgeuse is the brightest near-infrared source in the sky with a J band magnitude of −2.99; only about 13% of the star's radiant energy is emitted as visible light. If human eyes were sensitive to radiation at all wavelengths, Betelgeuse would appear as the brightest star in the night sky.


title: Betelgeuse

text: Catalogues list up to nine faint visual companions to Betelgeuse. They are at distances of about one to four arc-minutes and all are fainter than 10th magnitude.


title: Betelgeuse

text: Betelgeuse is generally considered to be a single isolated star and a runaway star, not currently associated with any cluster or star-forming region, although its birthplace is unclear.


title: Betelgeuse

text: Two spectroscopic companions to Betelgeuse have been proposed. Analysis of polarization data from 1968 through 1983 indicated a close companion with a periodic orbit of about 2.1 years, and by using speckle interferometry, the team concluded that the closer of the two companions was located at (≈9 AU) from the main star with a position angle of 273°, an orbit that would potentially place it within the star's chromosphere. The more distant companion was at (≈77 AU) with a position angle of 278°. Further studies have found no evidence for these companions or have actively refuted their existence, but the possibility of a close companion contributing to the overall flux has never been fully ruled out. High-resolution interferometry of Betelgeuse and its vicinity, far beyond the technology of the 1980s and 1990s, has not detected any companions.


title: Betelgeuse

text: Parallax is the apparent change of the position of an object, measured in seconds of arc, caused by the change of position of the observer of that object. As the Earth orbits the Sun, every star is seen to shift by a fraction of an arc second, which measure, combined with the baseline provided by the Earth's orbit gives the distance to that star. Since the first successful parallax measurement by Friedrich Bessel in 1838, astronomers have been puzzled by Betelgeuse's apparent distance. Knowledge of the star's distance improves the accuracy of other stellar parameters, such as luminosity that, when combined with an angular diameter, can be used to calculate the physical radius and effective temperature; luminosity and isotopic abundances can also be used to estimate the stellar age and mass.


title: Betelgeuse

text: In 1920, when the first interferometric studies were performed on the star's diameter, the assumed parallax was . This equated to a distance of or roughly , producing not only an inaccurate radius for the star but every other stellar characteristic. Since then, there has been ongoing work to measure the distance of Betelgeuse, with proposed distances as high as or about .


title: Betelgeuse

text: Before the publication of the Hipparcos Catalogue (1997), there were two slightly conflicting parallax measurements for Betelgeuse. The first, in 1991, gave a parallax of , yielding a distance of roughly or . The second was the Hipparcos Input Catalogue (1993) with a trigonometric parallax of , a distance of or . Given this uncertainty, researchers were adopting a wide range of distance estimates, leading to significant variances in the calculation of the star's attributes.


title: Betelgeuse

text: The results from the Hipparcos mission were released in 1997. The measured parallax of Betelgeuse was , which equated to a distance of roughly or , and had a smaller reported error than previous measurements. However, later evaluation of the Hipparcos parallax measurements for variable stars like Betelgeuse found that the uncertainty of these measurements had been underestimated. In 2007, an improved figure of was calculated, hence a much tighter error factor yielding a distance of roughly or .


title: Betelgeuse

text: In 2008, using the Very Large Array (VLA), produced a radio solution of , equaling a distance of or . As the researcher, Harper, points out: "The revised Hipparcos parallax leads to a larger distance () than the original; however, the astrometric solution still requires a significant cosmic noise of 2.4 mas. Given these results it is clear that the Hipparcos data still contain systematic errors of unknown origin." Although the radio data also have systematic errors, the Harper solution combines the datasets in the hope of mitigating such errors. An updated result from further observations with ALMA and e-Merlin gives a parallax of mas and a distance of pc or ly.


title: Betelgeuse

text: In 2020, new observational data from the space-based "Solar Mass Ejection Imager" aboard the Coriolis satellite and three different modeling techniques produced a refined parallax of mas, a radius of , and a distance of pc or ly, which, if accurate, would mean Betelgeuse is nearly 25% smaller and 25% closer to Earth than previously thought.


title: Betelgeuse

text: Although the European Space Agency's current Gaia mission was not expected to produce good results for stars brighter than the approximately V=6 saturation limit of the mission's instruments, actual operation has shown good performance on objects to about magnitude +3. Forced observations of brighter stars mean that final results should be available for all bright stars and a parallax for Betelgeuse will be published an order of magnitude more accurate than currently available. There is no data on Betelgeuse in Gaia Data Release 2.


title: Betelgeuse

text: Betelgeuse is classified as a semiregular variable star, indicating that some periodicity is noticeable in the brightness changes, but amplitudes may vary, cycles may have different lengths, and there may be standstills or periods of irregularity. It is placed in subgroup SRc; these are pulsating red supergiants with amplitudes around one magnitude and periods from tens to hundreds of days.


title: Betelgeuse

text: Betelgeuse typically shows only small brightness changes near to magnitude +0.5, although at its extremes it can become as bright as magnitude 0.0 or as faint as magnitude +1.6. Betelgeuse is listed in the General Catalogue of Variable Stars with a possible period of 2,335 days. More detailed analyses have shown a main period near 400 days, a short period of 185 days, and a longer secondary period around 2,100 days. The lowest reliably-recorded V-band magnitude of +1.614 was reported in February 2020.


title: Betelgeuse

text: Radial pulsations of red supergiants are well-modelled and show that periods of a few hundred days are typically due to fundamental and first overtone pulsation. Lines in the spectrum of Betelgeuse show doppler shifts indicating radial velocity changes corresponding, very roughly, to the brightness changes. This demonstrates the nature of the pulsations in size, although corresponding temperature and spectral variations are not clearly seen. Variations in the diameter of Betelgeuse have also been measured directly. First overtone pulsations of 185 days have been observed, and the ratio of the fundamental to overtone periods gives valuable information about the internal structure of the star and its age.


title: Betelgeuse

text: The source of the long secondary periods is unknown, but they cannot be explained by radial pulsations. Interferometric observations of Betelgeuse have shown hotspots that are thought to be created by massive convection cells, a significant fraction of the diameter of the star and each emitting 5–10% of the total light of the star. One theory to explain long secondary periods is that they are caused by the evolution of such cells combined with the rotation of the star. Other theories include close binary interactions, chromospheric magnetic activity influencing mass loss, or non-radial pulsations such as g-modes.


title: Betelgeuse

text: In addition to the discrete dominant periods, small-amplitude stochastic variations are seen. It is proposed that this is due to granulation, similar to the same effect on the sun but on a much larger scale.


title: Betelgeuse

text: On 13 December 1920, Betelgeuse became the first star outside the Solar System to have the angular size of its photosphere measured. Although interferometry was still in its infancy, the experiment proved a success. The researchers, using a uniform disk model, determined that Betelgeuse had a diameter of , although the stellar disk was likely 17% larger due to the limb darkening, resulting in an estimate for its angular diameter of about 0.055". Since then, other studies have produced angular diameters that range from 0.042 to . Combining these data with historical distance estimates of 180 to yields a projected radius of the stellar disk of anywhere from 1.2 to . Using the Solar System for comparison, the orbit of Mars is about , Ceres in the asteroid belt , Jupiter —so, assuming Betelgeuse occupying the place of the Sun, its photosphere might extend beyond the Jovian orbit, not quite reaching Saturn at .


title: Betelgeuse

text: The generally reported radii of large cool stars are Rosseland radii, defined as the radius of the photosphere at a specific optical depth of two-thirds. This corresponds to the radius calculated from the effective temperature and bolometric luminosity. The Rosseland radius differs from directly measured radii, with corrections for limb darkening and the observation wavelength. For example, a measured angular diameter of 55.6 mas would correspond to a Rosseland mean diameter of 56.2 mas, while further corrections for the existence of surrounding dust and gas shells would give a diameter of .


title: Betelgeuse

text: To overcome these challenges, researchers have employed various solutions. Astronomical interferometry, first conceived by Hippolyte Fizeau in 1868, was the seminal concept that has enabled major improvements in modern telescopy and led to the creation of the Michelson interferometer in the 1880s, and the first successful measurement of Betelgeuse. Just as human depth perception increases when two eyes instead of one perceive an object, Fizeau proposed the observation of stars through two apertures instead of one to obtain interferences that would furnish information on the star's spatial intensity distribution. The science evolved quickly and multiple-aperture interferometers are now used to capture speckled images, which are synthesized using Fourier analysis to produce a portrait of high resolution. It was this methodology that identified the hotspots on Betelgeuse in the 1990s. Other technological breakthroughs include adaptive optics, space observatories like Hipparcos, Hubble and Spitzer, and the Astronomical Multi-BEam Recombiner (AMBER), which combines the beams of three telescopes simultaneously, allowing researchers to achieve milliarcsecond spatial resolution.


title: Betelgeuse

text: Observations in different regions of the electromagnetic spectrum—the visible, near-infrared (NIR), mid-infrared (MIR), or radio—produce very different angular measurements. In 1996, Betelgeuse was shown to have a uniform disk of . In 2000, a Space Sciences Laboratory team measured a diameter of , ignoring any possible contribution from hotspots, which are less noticeable in the mid-infrared. Also included was a theoretical allowance for limb darkening, yielding a diameter of . The earlier estimate equates to a radius of roughly or , assuming the 2008 Harper distance of , a figure roughly the size of the Jovian orbit of .


title: Betelgeuse

text: In 2004, a team of astronomers working in the near-infrared announced that the more accurate photospheric measurement was . The study also put forth an explanation as to why varying wavelengths from the visible to mid-infrared produce different diameters: the star is seen through a thick, warm extended atmosphere. At short wavelengths (the visible spectrum) the atmosphere scatters light, thus slightly increasing the star's diameter. At near-infrared wavelengths (K and L bands), the scattering is negligible, so the classical photosphere can be directly seen; in the mid-infrared the scattering increases once more, causing the thermal emission of the warm atmosphere to increase the apparent diameter.


title: Betelgeuse

text: Studies with the IOTA and VLTI published in 2009 brought strong support to the idea of dust shells and a molecular shell (MOLsphere) around Betelgeuse, and yielded diameters ranging from 42.57 to with comparatively insignificant margins of error. In 2011, a third estimate in the near-infrared corroborating the 2009 numbers, this time showing a limb-darkened disk diameter of . The near-infrared photospheric diameter of at the Hipparcos distance of equates to about or . A 2014 paper derives an angular diameter of (equivalent to a uniform disc) using H and K band observations made with the VLTI AMBER instrument.


title: Betelgeuse

text: In 2009 it was announced that the radius of Betelgeuse had shrunk from 1993 to 2009 by 15%, with the 2008 angular measurement equal to . Unlike most earlier papers, this study used measurements at one specific wavelength over 15 years. The diminution in Betelgeuse's apparent size equates to a range of values between seen in 1993 to seen in 2008—a contraction of almost in . The observed contraction is generally believed to be a variation in just a portion of the extended atmosphere around Betelgeuse, and observations at other wavelengths have shown an increase in diameter over a similar period.


title: Betelgeuse

text: The latest models of Betelgeuse adopt a photospheric angular diameter of around , with multiple shells out to 50-. Assuming a distance of , this means a stellar diameter of .


title: Betelgeuse

text: Once considered as having the largest angular diameter of any star in the sky after the Sun, Betelgeuse lost that distinction in 1997 when a group of astronomers measured R Doradus with a diameter of , although R Doradus, being much closer to Earth at about , has a linear diameter roughly one-third that of Betelgeuse.


title: Betelgeuse

text: Betelgeuse is a very large, luminous but cool star classified as an M1-2 Ia-ab red supergiant. The letter "M" in this designation means that it is a red star belonging to the M spectral class and therefore has a relatively low photospheric temperature; the "Ia-ab" suffix luminosity class indicates that it is an intermediate-luminosity supergiant, with properties partway between a normal supergiant and a luminous supergiant. Since 1943, the spectrum of Betelgeuse has served as one of the stable anchor points by which other stars are classified.


title: Betelgeuse

text: Uncertainty in the star's surface temperature, diameter, and distance make it difficult to achieve a precise measurement of Betelgeuse's luminosity, but research from 2012 quotes a luminosity of around , assuming a distance of . Studies since 2001 report effective temperatures ranging from 3,250 to 3,690 K. Values outside this range have previously been reported, and much of the variation is believed to be real, due to pulsations in the atmosphere. The star is also a slow rotator and the most recent velocity recorded was —much slower than Antares which has a rotational velocity of . The rotation period depends on Betelgeuse's size and orientation to Earth, but it has been calculated to take to turn on its axis, inclined at an angle of around to Earth.


title: Betelgeuse

text: In 2004, astronomers using computer simulations speculated that even if Betelgeuse is not rotating it might exhibit large-scale magnetic activity in its extended atmosphere, a factor where even moderately strong fields could have a meaningful influence over the star's dust, wind and mass-loss properties. A series of spectropolarimetric observations obtained in 2010 with the Bernard Lyot Telescope at Pic du Midi Observatory revealed the presence of a weak magnetic field at the surface of Betelgeuse, suggesting that the giant convective motions of supergiant stars are able to trigger the onset of a small-scale dynamo effect.


title: Betelgeuse

text: Betelgeuse has no known orbital companions, so its mass cannot be calculated by that direct method. Modern mass estimates from theoretical modelling have produced values of , with values of – from older studies. It has been calculated that Betelgeuse began its life as a star of , based on a solar luminosity of 90,000–150,000. A novel method of determining the supergiant's mass was proposed in 2011, arguing for a current stellar mass of with an upper limit of 16.6 and lower of , based on observations of the star's intensity profile from narrow H-band interferometry and using a photospheric measurement of roughly or . Model fitting to evolutionary tracks give a current mass of , from an initial mass of .


title: Betelgeuse

text: The kinematics of Betelgeuse are complex. The age of Class M supergiants with an initial mass of is roughly 10 million years. Starting from its present position and motion a projection back in time would place Betelgeuse around farther from the galactic plane—an implausible location, as there is no star formation region there. Moreover, Betelgeuse's projected pathway does not appear to intersect with the 25 Ori subassociation or the far younger Orion Nebula Cluster (ONC, also known as Ori OB1d), particularly since Very Long Baseline Array astrometry yields a distance from Betelgeuse to the ONC of between 389 and . Consequently, it is likely that Betelgeuse has not always had its current motion through space but has changed course at one time or another, possibly the result of a nearby stellar explosion. An observation by the Herschel Space Observatory in January 2013 revealed that the star's winds are crashing against the surrounding interstellar medium.


title: Betelgeuse

text: The most likely star-formation scenario for Betelgeuse is that it is a runaway star from the Orion OB1 association. Originally a member of a high-mass multiple system within Ori OB1a, Betelgeuse was probably formed about 10–12 million years ago, but has evolved rapidly due to its high mass. In 2015, H. Bouy and J. Alves suggested that Betelgeuse may instead be a member of the newly discovered Taurion OB association.


title: Betelgeuse

text: In the late phase of stellar evolution, massive stars like Betelgeuse exhibit high rates of mass loss, possibly as much as every , resulting in a complex circumstellar environment that is constantly in flux. In a 2009 paper, stellar mass loss was cited as the "key to understanding the evolution of the universe from the earliest cosmological times to the current epoch, and of planet formation and the formation of life itself". However, the physical mechanism is not well understood. When Martin Schwarzschild first proposed his theory of huge convection cells, he argued it was the likely cause of mass loss in evolved supergiants like Betelgeuse. Recent work has corroborated this hypothesis, yet there are still uncertainties about the structure of their convection, the mechanism of their mass loss, the way dust forms in their extended atmosphere, and the conditions which precipitate their dramatic finale as a type II supernova. In 2001, Graham Harper estimated a stellar wind at every , but research since 2009 has provided evidence of episodic mass loss making any total figure for Betelgeuse uncertain. Current observations suggest that a star like Betelgeuse may spend a portion of its lifetime as a red supergiant, but then cross back across the H-R diagram, pass once again through a brief yellow supergiant phase and then explode as a blue supergiant or Wolf-Rayet star.


title: Betelgeuse

text: Astronomers may be close to solving this mystery. They noticed a large plume of gas extending at least six times its stellar radius indicating that Betelgeuse is not shedding matter evenly in all directions. The plume's presence implies that the spherical symmetry of the star's photosphere, often observed in the infrared, is "not" preserved in its close environment. Asymmetries on the stellar disk had been reported at different wavelengths. However, due to the refined capabilities of the NACO adaptive optics on the VLT, these asymmetries have come into focus. The two mechanisms that could cause such asymmetrical mass loss, were large-scale convection cells or polar mass loss, possibly due to rotation. Probing deeper with ESO's AMBER, gas in the supergiant's extended atmosphere has been observed vigorously moving up and down, creating bubbles as large as the supergiant itself, leading his team to conclude that such stellar upheaval is behind the massive plume ejection observed by Kervella.


title: Betelgeuse

text: In addition to the photosphere, six other components of Betelgeuse's atmosphere have now been identified. They are a molecular environment otherwise known as the MOLsphere, a gaseous envelope, a chromosphere, a dust environment and two outer shells (S1 and S2) composed of carbon monoxide (CO). Some of these elements are known to be asymmetric while others overlap.


title: Betelgeuse

text: At about 0.45 stellar radii (~2–) above the photosphere, there may lie a molecular layer known as the MOLsphere or molecular environment. Studies show it to be composed of water vapor and carbon monoxide with an effective temperature of about . Water vapor had been originally detected in the supergiant's spectrum in the 1960s with the two Stratoscope projects but had been ignored for decades. The MOLsphere may also contain SiO and AlO—molecules which could explain the formation of dust particles.


title: Betelgeuse

text: The asymmetric gaseous envelope, another cooler region, extends for several radii (~10–) from the photosphere. It is enriched in oxygen and especially in nitrogen relative to carbon. These composition anomalies are likely caused by contamination by CNO-processed material from the inside of Betelgeuse.


title: Betelgeuse

text: Radio-telescope images taken in 1998 confirm that Betelgeuse has a highly complex atmosphere, with a temperature of , similar to that recorded on the star's surface but much lower than surrounding gas in the same region. The VLA images also show this lower-temperature gas progressively cools as it extends outward. Although unexpected, it turns out to be the most abundant constituent of Betelgeuse's atmosphere. "This alters our basic understanding of red-supergiant star atmospheres", explained Jeremy Lim, the team's leader. "Instead of the star's atmosphere expanding uniformly due to gas heated to high temperatures near its surface, it now appears that several giant convection cells propel gas from the star's surface into its atmosphere." This is the same region in which Kervella's 2009 finding of a bright plume, possibly containing carbon and nitrogen and extending at least six photospheric radii in the southwest direction of the star, is believed to exist.


title: Betelgeuse

text: The chromosphere was directly imaged by the Faint Object Camera on board the Hubble Space Telescope in ultraviolet wavelengths. The images also revealed a bright area in the southwest quadrant of the disk. The average radius of the chromosphere in 1996 was about 2.2 times the optical disk (~) and was reported to have a temperature no higher than . However, in 2004 observations with the STIS, Hubble's high-precision spectrometer, pointed to the existence of warm chromospheric plasma at least one arcsecond away from the star. At a distance of , the size of the chromosphere could be up to . The observations have conclusively demonstrated that the warm chromospheric plasma spatially overlaps and co-exists with cool gas in Betelgeuse's gaseous envelope as well as with the dust in its circumstellar dust shells.


title: Betelgeuse

text: The first claim of a dust shell surrounding Betelgeuse was put forth in 1977 when it was noted that dust shells around mature stars often emit large amounts of radiation in excess of the photospheric contribution. Using heterodyne interferometry, it was concluded that the red supergiant emits most of its excess radiation from positions beyond 12 stellar radii or roughly the distance of the Kuiper belt at 50 to 60 AU, which depends on the assumed stellar radius. Since then, there have been studies done of this dust envelope at varying wavelengths yielding decidedly different results. Studies from the 1990s have estimated the inner radius of the dust shell anywhere from 0.5 to , or 100 to . These studies point out that the dust environment surrounding Betelgeuse is not static. In 1994, it was reported that Betelgeuse undergoes sporadic decades-long dust production, followed by inactivity. In 1997, significant changes in the dust shell's morphology in one year were noted, suggesting that the shell is asymmetrically illuminated by a stellar radiation field strongly affected by the existence of photospheric hotspots. The 1984 report of a giant asymmetric dust shell () has not been corroborated by recent studies, although another published the same year said that three dust shells were found extending four light-years from one side of the decaying star, suggesting that Betelgeuse sheds its outer layers as it moves.


title: Betelgeuse

text: Although the exact size of the two outer CO shells remains elusive, preliminary estimates suggest that one shell extends from about 1.5 to 4.0 arcseconds and the other expands as far as 7.0 arcseconds. Assuming the Jovian orbit of as the star radius, the inner shell would extend roughly 50 to 150 stellar radii (~300 to ) with the outer one as far as 250 stellar radii (~). The Sun's heliopause is estimated at about 100 AU, so the size of this outer shell would be almost fourteen times the size of the Solar System.


title: Betelgeuse

text: Betelgeuse is travelling supersonically through the interstellar medium at a speed of (i.e. ~) creating a bow shock. The shock is not created by the star, but by its powerful stellar wind as it ejects vast amounts of gas into the interstellar medium at a speed of , heating the material surrounding the star, thereby making it visible in infrared light. Because Betelgeuse is so bright, it was only in 1997 that the bow shock was first imaged. The cometary structure is estimated to be at least one parsec wide, assuming a distance of 643 light-years.


title: Betelgeuse

text: Hydrodynamic simulations of the bow shock made in 2012 indicate that it is very young—less than 30,000 years old—suggesting two possibilities: that Betelgeuse moved into a region of the interstellar medium with different properties only recently or that Betelgeuse has undergone a significant transformation producing a changed stellar wind. A 2012 paper, proposed that this phenomenon was caused by Betelgeuse transitioning from a blue supergiant (BSG) to a red supergiant (RSG). There is evidence that in the late evolutionary stage of a star like Betelgeuse, such stars "may undergo rapid transitions from red to blue and vice versa on the Hertzsprung-Russell diagram, with accompanying rapid changes to their stellar winds and bow shocks." Moreover, if future research bears out this hypothesis, Betelgeuse may prove to have traveled close to 200,000 AU as a red supergiant scattering as much as along its trajectory.


title: Betelgeuse

text: Betelgeuse is a red supergiant that has evolved from an O-type main sequence star. Its core will eventually collapse, producing a supernova explosion and leaving behind a compact remnant. The details depend on the exact initial mass and other physical properties of that main sequence star.


title: Betelgeuse

text: The initial mass of Betelgeuse can only be estimated by testing different stellar evolutionary models to match its current observed properties. The unknowns of both the models and the current properties mean that there is considerable uncertainty in Betelgeuse's initial appearance, but its mass is usually estimated to have been in the range of , with modern models finding values of . Its chemical makeup can be reasonably assumed to have been around 70% hydrogen, 28% helium, and 2.4% heavy elements, slightly more metal-rich than the Sun but otherwise similar. The initial rotation rate is more uncertain, but models with slow to moderate initial rotation rates produce the best matches to Betelgeuse's current properties. That main sequence version of Betelgeuse would have been a hot luminous star with a spectral type such as O9V.


title: Betelgeuse

text: A star would take between 11.5 and 15 million years to reach the red supergiant stage, with more rapidly-rotating stars taking the longest. Rapidly-rotating stars take 9.3 million years to reach the red supergiant stage, while stars with slow rotation take only 8.1 million years. These are the best estimates of Betelgeuse's current age, as the time since its zero age main sequence stage is estimated to be 8.0–8.5 million years as a star with no rotation.


title: Betelgeuse

text: Betelgeuse's time spent as a red supergiant can be estimated by comparing mass loss rates to the observed circumstellar material, as well as the abundances of heavy elements at the surface. Estimates range from 20,000 years to a maximum of 140,000 years. Betelgeuse appears to undergo short periods of heavy mass loss and is a runaway star moving rapidly through space, so comparisons of its current mass loss to the total lost mass are difficult.


title: Betelgeuse

text: The surface of Betelgeuse shows enhancement of nitrogen, relatively low levels of carbon, and a high proportion of C relative to C, all indicative of a star that has experienced the first dredge-up. However, the first dredge-up occurs soon after a star reaches the red supergiant phase and so this only means that Betelgeuse has been a red supergiant for at least a few thousand years. The best prediction is that Betelgeuse has already spent around 40,000 years as a red supergiant, having left the main sequence perhaps one million years ago.


title: Betelgeuse

text: The current mass can be estimated from evolutionary models from the initial mass and the expected mass lost so far. For Betelgeuse, the total mass lost is predicted to be no more than about , giving a current mass of , considerably higher than estimated by other means such as pulsational properties or limb-darkening models.


title: Betelgeuse

text: Betelgeuse's mass can also be estimated based on its position on the colormagnitudediagram (CMD). Betelgeuse's color may have changed from yellow (or possibly orange) to red in the last few thousand years, based on a 2022 review of historical records. This color change combined with CMD suggest a mass of and age of 14 Myr.


title: Betelgeuse

text: All stars more massive than about are expected to end their lives when their cores collapse, typically producing a supernova explosion. Up to about , a type II-P supernova is always produced from the red supergiant stage.


title: Betelgeuse

text: More massive stars can lose mass quickly enough that they evolve towards higher temperatures before their cores can collapse, particularly for rotating stars and models with especially high mass loss rates. These stars can produce type II-L or type IIb supernovae from yellow or blue supergiants, or type I b/c supernovae from Wolf-Rayet stars.


title: Betelgeuse

text: Models of rotating stars predict a peculiar type II supernova similar to SN 1987A from a blue supergiant progenitor. On the other hand, non-rotating models predict a type II-P supernova from a red supergiant progenitor.


title: Betelgeuse

text: The time until Betelgeuse explodes depends on the predicted initial conditions and on the estimate of the time already spent as a red supergiant. The total lifetime from the start of the red supergiant phase to core collapse varies from about 300,000 years for a rotating star, 550,000 years for a rotating star, and up to a million years for a non-rotating star. Given the estimated time since Betelgeuse became a red supergiant, estimates of its remaining lifetime range from a "best guess" of under 100,000 years for a non-rotating model to far longer for rotating models or lower-mass stars. Betelgeuse's suspected birthplace in the Orion OB1 association is the location of several previous supernovae. It is believed that runaway stars may be caused by supernovae, and there is strong evidence that OB stars μ Columbae, AE Aurigae, and 53 Arietis all originated from such explosions in Ori OB1 2.2, 2.7, and 4.9 million years ago.


title: Betelgeuse

text: A typical type II-P supernova emits of neutrinos and produces an explosion with a kinetic energy of . As seen from Earth, Betelgeuse as a type IIP supernova would have a peak apparent magnitude somewhere in the range −8 to −12.


title: Betelgeuse

text: This would be easily visible in daylight, with a possible brightness up to a significant fraction of the full moon, though likely not exceeding it. This type of supernova would remain at roughly constant brightness for 2–3 months before rapidly dimming. The visible light is produced mainly by the radioactive decay of cobalt, and sustains its brightness due to the increasing transparency of the cooling hydrogen ejected by the supernova.


title: Betelgeuse

text: Due to misunderstandings caused by the 2009 publication of the star's 15% contraction, apparently of its outer atmosphere, Betelgeuse has frequently been the subject of scare stories and rumors suggesting that it will explode within a year, and leading to exaggerated claims about the consequences of such an event.


title: Betelgeuse

text: The timing and prevalence of these rumors have been linked to broader misconceptions of astronomy, particularly to doomsday predictions relating to the Mayan calendrical apocalypse.


title: Betelgeuse

text: Betelgeuse is not likely to produce a gamma-ray burst and is not close enough for its X-rays, ultraviolet radiation, or ejected material to cause significant effects on Earth.


title: Betelgeuse

text: Following the dimming of Betelgeuse in December 2019, reports appeared in the science and mainstream media that again included speculation that the star might be about to go supernova – even in the face of scientific research that a supernova is not expected for perhaps 100,000 years.


title: Betelgeuse

text: Some outlets reported the magnitude as faint as +1.3 as an unusual and interesting phenomenon, like "Astronomy" magazine, the "National Geographic", and the "Smithsonian".


title: Betelgeuse

text: reported that a supernova was possible but unlikely, whilst other outlets falsely portrayed a supernova as an imminent realistic possibility. CNN, for example, chose the headline "A giant red star is acting weird and scientists think it may be about to explode",


title: Betelgeuse

text: Phil Plait, in his "Bad Astronomy" blog, noting that Betelgeuse's recent behaviour, "[w]hile unusual . . . isn't unprecedented," argued that the star is not likely to explode "for a long, long time."


title: Betelgeuse

text: Dennis Overbye of "The New York Times" agreed that an explosion was not imminent but added that "astronomers are having fun thinking about it."


title: Betelgeuse

text: Following the eventual supernova, a small dense remnant will be left behind, either a neutron star or black hole. Betelgeuse does not seem to have a core massive enough for a black hole, so the remnant will probably be a neutron star of approximately .


title: Betelgeuse

text: "Betelgeux" and "Betelgeuze" were used until the early 20th century, when the spelling "Betelgeuse" became universal.


title: Betelgeuse

text: The "-urz" pronunciations are attempts to render the French "eu" sound; they only work in "r"-dropping accents.


title: Betelgeuse

text: Betelgeuse is often mistranslated as "armpit of the central one". In his 1899 work "Star-Names and Their Meanings", American amateur naturalist Richard Hinckley Allen stated the derivation was from the "", which he claimed degenerated into a number of forms including "Bed Elgueze", "Beit Algueze", "Bet El-gueze", "Beteigeuze" and more, to the forms "Betelgeuse", "Betelguese", "Betelgueze" and "Betelgeux". The star was named "Beldengeuze" in the "Alfonsine Tables", and Italian Jesuit priest and astronomer Giovanni Battista Riccioli had called it "Bectelgeuze" or "Bedalgeuze".


title: Betelgeuse

text: Paul Kunitzsch, Professor of Arabic Studies at the University of Munich, refuted Allen's derivation and instead proposed that the full name is a corruption of the Arabic "", meaning "the Hand of "al-Jauzā<nowiki>'"</nowiki>"; "i.e.", Orion.


title: Betelgeuse

text: European mistransliteration into medieval Latin led to the first character "y" (ﻴ, with two dots underneath) being misread as a "b" (ﺒ, with only one dot underneath).


title: Betelgeuse

text: During the Renaissance, the star's name was written as ' ("house of Orion") or ', incorrectly thought to mean "armpit of Orion" (a true translation of "armpit" would be , transliterated as ")". This led to the modern rendering as "Betelgeuse". Other writers have since accepted Kunitzsch's explanation.


title: Betelgeuse

text: The last part of the name, "-elgeuse", comes from the Arabic ', a historical Arabic name of the constellation Orion, a feminine name in old Arabian legend, and of uncertain meaning. Because ', the root of ', means "middle", ' roughly means "the Central One". The modern Arabic name for Orion is ' ("the Giant"), although the use of ' in the name of the star has continued. The 17th-century English translator Edmund Chilmead gave it the name "Ied Algeuze" ("Orion's Hand"), from Christmannus. Other Arabic names recorded include ' ("the Right Hand"), ' ("the Arm"), and ' ("the Shoulder"), all of al-Jauzā, Orion, as '.


title: Betelgeuse

text: Other names for Betelgeuse included the Persian ' "the Arm", and Coptic ' "an Armlet". "" was its Sanskrit name, as part of a Hindu understanding of the constellation as a running antelope or stag. In traditional Chinese astronomy, the name for Betelgeuse is (", the Fourth Star of the constellation of Three Stars") as the Chinese constellation originally referred to the three stars in the girdle of Orion. This constellation was ultimately expanded to ten stars, but the earlier name stuck. In Japan, the Taira, or Heike, clan adopted Betelgeuse and its red color as its symbol, calling the star "Heike-boshi", (), while the Minamoto, or Genji, clan had chosen Rigel and its white color. The two powerful families fought a legendary war in Japanese history, the stars seen as facing each other off and only kept apart by the Belt.


title: Betelgeuse

text: In Tahitian lore, Betelgeuse was one of the pillars propping up the sky, known as "Anâ-varu", the pillar to sit by. It was also called "Ta'urua-nui-o-Mere" "Great festivity in parental yearnings". A Hawaiian term for it was "Kaulua-koko" "brilliant red star". The Lacandon people of Central America knew it as "chäk tulix" "red butterfly".


title: Betelgeuse

text: Astronomy writer Robert Burnham Jr. proposed the term "padparadaschah" which denotes a rare orange sapphire in India, for the star.


title: Betelgeuse

text: With the history of astronomy intimately associated with mythology and astrology before the scientific revolution, the red star, like the planet Mars that derives its name from a Roman war god, has been closely associated with the martial archetype of conquest for millennia, and by extension, the motif of death and rebirth. Other cultures have produced different myths. Stephen R. Wilk has proposed the constellation of Orion could have represented the Greek mythological figure Pelops, who had an artificial shoulder of ivory made for him, with Betelgeuse as the shoulder, its color reminiscent of the reddish yellow sheen of ivory.


title: Betelgeuse

text: Aboriginal people from the Great Victoria Desert of South Australia incorporated Betelgeuse into their oral traditions as the club of Nyeeruna (Orion), which fills with fire-magic and dissipates before returning. This has been interpreted as showing that early Aboriginal observers were aware of the brightness variations of Betelgeuse. The Wardaman people of northern Australia knew the star as "Ya-jungin" "Owl Eyes Flicking", its variable light signifying its intermittent watching of ceremonies led by the Red Kangaroo Leader Rigel. In South African mythology, Betelgeuse was perceived as a lion casting a predatory gaze toward the three zebras represented by Orion's Belt.


title: Betelgeuse

text: In the Americas, Betelgeuse signifies a severed limb of a man-figure (Orion)—the Taulipang of Brazil know the constellation as Zililkawai, a hero whose leg was cut off by his wife, with the variable light of Betelgeuse linked to the severing of the limb. Similarly, the Lakota people of North America see it as a chief whose arm has been severed.


title: Betelgeuse

text: A Sanskrit name for Betelgeuse is ārdrā "the moist one", eponymous of the "Ardra" lunar mansion in Hindu astrology. The Rigvedic God of storms Rudra presided over the star; this association was linked by 19th-century star enthusiast to Orion's stormy nature. The constellations in Macedonian folklore represented agricultural items and animals, reflecting their village way of life. To them, Betelgeuse was "Orach" "the ploughman", alongside the rest of Orion which depicted a plough with oxen. The rising of Betelgeuse at around 3 a.m. in late summer and autumn signified the time for village men to go to the fields and plough. To the Inuit, the appearance of Betelgeuse and Bellatrix high in the southern sky after sunset marked the beginning of spring and lengthening days in late February and early March. The two stars were known as "Akuttujuuk" "those (two) placed far apart", referring to the distance between them, mainly to people from North Baffin Island and Melville Peninsula.


title: Betelgeuse

text: The opposed locations of Orion and Scorpius, with their corresponding bright red variable stars Betelgeuse and Antares, were noted by ancient cultures around the world. The setting of Orion and rising of Scorpius signify the death of Orion by the scorpion. In China they signify brothers and rivals Shen and Shang. The Batak of Sumatra marked their New Year with the first new moon after the sinking of Orion's Belt below the horizon, at which point Betelgeuse remained "like the tail of a rooster". The positions of Betelgeuse and Antares at opposite ends of the celestial sky were considered significant and their constellations were seen as a pair of scorpions. Scorpion days marked as nights that both constellations could be seen.


title: Betelgeuse

text: As one of the brightest and best-known stars, Betelgeuse has featured in many works of fiction. The star's unusual name inspired the title of the 1988 film "Beetlejuice", referring to its titular antagonist, and script writer Michael McDowell was impressed by how many people made the connection. In the popular science fiction series "The Hitchhiker's Guide to the Galaxy" by Douglas Adams, Ford Prefect was from "a small planet somewhere in the vicinity of Betelgeuse."


title: Betelgeuse

text: Two American navy ships were named after the star, both of them World War II vessels, the launched in 1939 and launched in 1944. In 1979, a French supertanker named "Betelgeuse" was moored off Whiddy Island discharging oil when it exploded, killing 50 people in one of the worst disasters in Ireland's history.


title: Betelgeuse

text: The Dave Matthews Band song "Black and Blue Bird" references the star. The Blur song "Far Out" from their 1994 album Parklife mentions Betelgeuse in its lyrics.