V4641 Sagittarii

V4641 Sagittarii
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Sagittarius
Right ascension 18h 19m 21.63s
Declination -25° 24′ 25.8″
Other designations
V4641 Sagittarii, V4641 Sgr, GSC 06848-03786, SAX J1819.3-2525, 2MASS J18192163-2524258, AAVSO 1813-25B
Database references
SIMBAD data

V4641 Sagittarii (V4641 Sgr) is a variable X-ray binary star system in the constellation Sagittarius. It is the source of one of the fastest superluminal jets in our galaxy.

In 1999 a violent outburst at V4641 Sgr revealed it to be the closest known black hole to Earth. Originally thought to be positioned approximately 1,600 light-years (100,000,000 AU) from Earth[1], later observations showed it to be at least 15 times further away.[2]

References

  1. ^ "Dramatic Outburst Reveals Nearest Black Hole". National Radio Astronomy Observatory. http://www.nrao.edu/pr/2000/v4641/. Retrieved 2008-08-30. 
  2. ^ A Black Hole in the Superluminal Source SAX J1819.3-2525 (V4641 SGR), 2001: "Finally, we find a distance in the range 7.40 ≤ d ≤ 12.31 kpc (90% confidence), which is at least a factor of ≈ 15 larger than the initially assumed distance of ≈ 1,600 light-years/500 pc."

External links

Coordinates: 18h 19m 21.636s, −25° 24′ 25.6″