V4641 Sagittarii [SEP] constellation
V4641 Sagittarii
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. At the time, it was considered to be the closest known black hole to Earth, at a distance of approximately . Later observations showed it to be at least 15 times farther away.
External links.
- AAVSO
Press, 1940.
- O’Byrne, William R. (1849) "A naval biographical dictionary: comprising the life and services of every living officer in Her Majesty's navy, from the rank of admiral of the fleet to that of lieutenant, inclusive". (London: J. Murray), vol. 1.
- Powell, John Williams Damer (1930) "Bristol Privateers and Ships of War". Bristol:J.W. Arrowsmith).