V404 Лебедя

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V404 Лебедя (V404 Cygni) — подвійна зоря, що складається з чорної дірки масою в 12±маса Сонця[1] та супутника-зірки класу G або K з масою, трохи меншою за Сонце в сузір’ї Лебідь (Cygnus). The two stars orbit each other every 6.5 d at fairly close range. Due to their close proximity the main sequence star would be distorted into egg shape by the black hole's gravity and lose mass to the black hole.

The "V" in the name indicates that it is a variable star, which repeatedly gets brighter and fainter over time. It is also considered a nova, because at least three times in the 20th century it produced a bright outburst of energy. Finally, it is a soft X-ray transient because it periodically emits short bursts of X-rays.

В 2009, the black hole in the V404 Cygni system became the first black hole to have an accurate parallax measurement for its distance from our solar system; the distance is 2.39±0.14 kiloparsecs,[2] or (7.80±0.46)×103 light-years.

Відкриття[ред. | ред. код]

22 травня 1989 року Japanese Ginga Team відкрила нове джерело гама-випромінювання, яке позначили як GS 2023+338. Це This source was subsequently identified as coincident in position with a previously known nova cataloged as V404 Cygni.

Спалах у 2015[ред. | ред. код]

15 червня 2015 року супутник NASA Swift помітив відновлення активності. A worldwide observing campaign was commenced and on 17 June ESA's INTEGRAL Gamma-ray observatory started monitoring the outburst. INTEGRAL has been detecting "repeated bright flashes of light time scales shorter than an hour, something rarely seen in other black hole systems", and during these flashes V404 Cygni is the brightest object in the X-ray sky - up to fifty times brighter than the Crab Nebula. This outburst is the first since 1989. Other outbursts occurred in 1938 and 1956, and the outbursts are probably caused by material piling up in a disk around the black hole until a tipping point is reached.[3]

Примітки[ред. | ред. код]

  1. Shahbaz, T.; Ringwald, F. A.; Bunn, J. C.; Naylor, T. та ін. (1994). The mass of the black hole in V404 Cygni. MNRAS 271: L1–L14. Bibcode:1994MNRAS.271L..10S. 
  2. Miller-Jones, J. A. C.; Jonker; Dhawan. The first accurate parallax distance to a black hole. The Astrophysical Journal Letters 706 (2): L230. Bibcode:2009ApJ...706L.230M. arXiv:0910.5253. doi:10.1088/0004-637X/706/2/L230. 
  3. Monster Black Hole Wakes Up After 26 Years. integral. ESA. Архів оригіналу за 26 червень 2015. Процитовано 26 June 2015. 
  • "V404 Cyg: 10 years in quiescence" Elena P. Pavlenko, Yuliana G. Kuznetsova, Sergei Yu. Shugarov and Vladislav S. Petrov. Astrophysics and Space Science Supplement, 276, pp. 65-66
  • "The 1989 outburst of V404 cygni: A very unusual x-ray nova" R. M. Wagner, S. Starrfield, A. Cassatella, R. Gonzalez-Riestra, T. J. Kreidl, S. B. Howell, R. M. Hjellming, X. -H. Han, G. Sonneborn