5 astronomical trivia of the week #AstroMiniBR [09/07]

Every Friday, the TechWorld and AstroMiniBR bring together five relevant and fun astronomical curiosities produced by the contributors to the Twitter profile to disseminate knowledge of this science, which is the oldest of all!

This week we have gravitational waves; an Earth-sized telescope; the weight of a star; and more. Come on?

#1: Look at the wave! (or just watch the wave!)

With gravity wave data from 2015, MIT physicists were able to prove Hawking’s theorem! When two black holes merge, some of the system’s mass is expelled through waves in the fabric of spacetime, which we call gravitational waves. The first time they were detected was in 2015. Now, this new form of knowledge continues to expand the horizon of human knowledge!

In 1971, Stephen Hawking mathematically proposed that the area of ​​the event horizon of a black hole could never shrink. This means that after the fusion of two black holes, the total area before the fusion must be the same as the total area after the fusion. 50 years later and observations prove the theorem!

#2: An Earth-sized telescope

The larger a telescope, we can observe smaller objects in the sky. Now how big can a telescope be? The largest physical telescope in the world is in China and is 500 meters in diameter. The limits of engineering are tested every time astronomers need bigger eyes to look at the sky.

Now, what about an Earth-sized telescope? A technique called interferometry allows us to combine observations from different telescopes at different locations on Earth and the distance between them is the equivalent of a virtual telescope! If you put a telescope in Rio de Janeiro and another in São Paulo it would be like having a virtual telescope 600 km in diameter! With this technique, collaboration Event Horizon Telescope used telescopes at different points on the globe to create an Earth-sized virtual telescope and observe, for the first time, a black hole!

Earth Location of Observatories Participating in the Event Horizon Telescope Collaboration, Creating an Earth-Size Virtual Telescope!Source:  ESO

#3: Leaving the Solar System in 3, 2, 1…

How far is the presence of humanity in the Universe?! With astronomy we can observe very far away, but how far have we gone? The farthest human probe is Voyager 1, which has been traveling for 55 years! It was the first probe to leave the Solar System and it will take a few thousand more years to reach the star closest to us! It seems that humans still need to master space travel if we are to see more places!

#4: One is too little, two is good and three is too much

How heavy can a star be? Could a star 300 times the mass of the Sun exist? It wasn’t this time! The first observations of the star at the center of nebula NGC 6357 left astronomers confused because it indicated the presence of a star much more massive than theoretical limits predicted from stellar physics.

With observations from the Hubble Telescope, which has a higher resolution, it was possible to see that we actually have 3 star light in what looks like one! These 3 stars are still quite massive, a few hundred times the mass of the Sun, but they are within the limits of physics.

#5: Shakespeare in Heaven!

Perdita is one of Uranus’ moons! By its distance, its existence has been called into question more than once. The first time it was detected was in 1986, by the Voyager 2 spacecraft. After that, it took more than a decade to be observed again. In 1999 it was observed again, but its existence was questioned again in 2001, when it was no longer considered a natural satellite of Uranus. Finally, in 2003, the Hubble telescope was able to detect it again!

#Bonus: A Fatal Supernova?

Was a supernova responsible for the extinction of the Upper Devonian period? A study seeks to investigate this question through the analysis of isotopes of Plutonium and Samarius, found in some fossils from that time.

It turns out that these isotopes don’t happen naturally on Earth, but they happen in supernovae! A supernova, when it explodes, has a large ultraviolet emission, which could destroy the ozone layer and decimate 75% of life on Earth.

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