| 词条 | V4641 Sagittarii |
| 释义 |
|name=V4641 Sagittarii }}{{Starbox observe |epoch = J2000.0 |ra = {{RA|18|19|21.63}} |dec = {{DEC|-25|24|25.8}} |constell = Sagittarius }}{{Starbox catalog |names=V4641 Sagittarii, V4641 Sgr, GSC 06848-03786, SAX J1819.3-2525, 2MASS J18192163-2524258, AAVSO 1813-25B, XTE J1819-254 }}{{Starbox reference |Simbad=V4641+Sagittarii }}{{Starbox end}} 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 the Milky Way galaxy. In 1999 a violent X-ray outburst revealed it to contain a black hole.[1] At the time, it was considered to be the closest known black hole to Earth, at a distance of approximately {{convert|1600|ly|parsec|lk=on}}. Later observations showed it to be at least 15 times farther away.[2] References1. ^{{cite web|title=Dramatic Outburst Reveals Nearest Black Hole|url=http://www.nrao.edu/pr/2000/v4641/|publisher=National Radio Astronomy Observatory|accessdate=2008-08-30}} 2. ^[https://arxiv.org/abs/astro-ph/0103045v1 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
4 : Stellar black holes|Sagittarius (constellation)|Microquasars|Objects with variable star designations |
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