SGR 1806-20

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SGR 1806-20
SGR 1806-20 108685main SRB1806 20rev2.jpg
Observation data
Epoch J2000      Equinox J2000
Constellation Sagittarius
Right ascension 18h 08m 39.32s
Declination −20° 24' 39.5"'
Apparent magnitude (V) totally obscured
Distance 50,000 light-years (14.5 kiloparsecs)
Mass 12.391 M
Radius 0.0000025 R
Luminosity 3000000 L
Other designations
GRB 790107, INTEGRAL1 84, AX 1805.7-2025 GRB 970912, INTREF 882, CXOU J180839.3-202439, HETE Trigger 1566, KONUS 07.01.79, EQ 1805.7-2025, HETE Trigger 3801, PSR J1808-2024, GBS 1806-20, HETE Trigger 3800, RX J1808.6-2024.

SGR 1806-20 is a magnetar, a particular type of neutron star. It was discovered in 1979 and has been identified as a soft gamma repeater. SGR 1806-20 is located about 14.5 kiloparsecs (50,000 light-years) from Earth on the far side of our Milky Way galaxy in the constellation of Sagittarius. It has a diameter of no more than 20 kilometres (12 mi) and rotates on its axis every 7.5 seconds (30,000 km/h rotation speed at the surface). As of 2012, SGR 1806-20 is the most highly magnetized object ever observed, with a magnetic field over 1015 gauss (1011 tesla) in intensity[1] (compared to the Sun's 1–5 gauss). SGR 1806-20 has a magnetic field that is a quadrillion (short scale) times stronger than that of the Earth.



A similar blast within 3 parsecs (10 light years) of Earth would destroy the ozone layer and would be similar in effect to a 12 kt of TNT (50 TJ) nuclear blast at 7.5 km. The nearest known magnetar to earth is 1E 1048.1-5937, located 9,000 light-years away in the constellation Carina.


SGR 1806-20 lies at the core of radio nebula G10.0-0.3 and is a component of cluster 1806-20, itself a component of W31, one of the largest H II regions in the Milky Way. Cluster 1806-20 is made up of some highly unusual stars, including at least two carbon-rich Wolf–Rayet stars (WC9d and WCL), two blue hypergiants, and LBV 1806-20, one of the brightest/most massive stars in the galaxy.

See also[edit]


  • ^1 As measured by various space-based and land-based astronomical observatories, including the Swift spacecraft.


  1. ^ "Top story – Scientists measure the most powerful magnet known". NASA, Goddard Space Flight Center. 2002-11-04. Archived from the original on 2010-04-28. Retrieved 2011-12-29. 
  2. ^ "Cosmic Explosion Among the Brightest in Recorded History". NASA, Goddard Space Flight Center. 2005-02-18. Retrieved 2011-12-29. 

External links[edit]

Coordinates: Sky map 18h 08m 39.32s, −20° 24′ 39.5″