GS 2000+25

GS 2000+25

Near-infrared (I band) light curves for QZ Vulpeculae, adapted from Chevalier and Ilovaisky (1993). The data were collected over a 10 night period in July 1991. Data collected on different nights are plotted with different colors. The shape of the light curve changed over a period of approximately two days, leading to different shapes on even or odd numbered days.
Observation data
Epoch J2000      Equinox ICRS
Constellation Vulpecula
Right ascension 20h 02m 49.58s
Declination +25° 14′ 11.3″
Apparent magnitude (V) 18.2
Characteristics
Spectral type Black hole + K3-6 V
Astrometry
Distance8800 ± 2300 ly
(2700 ± 700 pc)
Orbit
Period (P)8.26 hr
Details
Black hole
Mass7.2–7.8 M☉
Other designations
Nova Vul 1988, INTREF 1007, QZ Vul
Database references
SIMBADdata

GS 2000+25 is an X-ray binary system in the constellation Vulpecula, consisting of a late K-type star and a black hole. It is also an X-ray nova.

Fumiyoshi Makino and the Ginga satellite team discovered GS 2000+25, in April 1988. A few days later a star, variable in visible light, was identified at its position. It received its variable star designation, QZ Vulpeculae, in 1989.

Properties

Because the black hole is more massive than the companion star, it is the primary of the system. The black hole has a mass of about 5 solar masses while the companion has a mass of about 0.5 solar masses. Because the companion star has a low mass, the system is a low-mass X-ray binary.

See also

References

  1. ↑ Chevalier, C.; Ilovaisky, S. A. (March 1993). "Optical studies of transient low-mass X-ray binaries. IV. A 10-hour distorsion wave in the quiescent light curve of GS 2000+25". Astronomy and Astrophysics. 269: 301–309. Bibcode:1993A&A...269..301C. Retrieved 23 April 2025.
  2. ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
  3. 1 2 3 4 Liu, Q. Z; Van Paradijs, J; Van Den Heuvel, E. P. J (2007). "A catalogue of low-mass X-ray binaries in the Galaxy, LMC, and SMC (Fourth edition)". Astronomy & Astrophysics. 469 (2): 807. arXiv:0707.0544. Bibcode:2007A&A...469..807L. doi:10.1051/0004-6361:20077303. S2CID 14673570.
  4. 1 2 Yungelson, L; Lasota, J.-P (2008). "Evolution of low-mass binaries with black-hole components". New Astronomy Reviews. 51 (10–12): 860–868. arXiv:0801.3433. Bibcode:2008NewAR..51..860Y. doi:10.1016/j.newar.2008.03.017. S2CID 11830754.
  5. ↑ Reynolds, Mark T; Callanan, Paul J; Robinson, Edward L; Froning, Cynthia S (2008). "Infrared contamination in Galactic X-ray novae". Monthly Notices of the Royal Astronomical Society. 387 (2): 788. arXiv:0804.0370. Bibcode:2008MNRAS.387..788R. doi:10.1111/j.1365-2966.2008.13272.x. S2CID 16918671.
  6. ↑ "GS 2000+25". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 26 November 2017.
  7. ↑ Marsden, Brian G. (28 April 1988). "X-Ray Sources". IAU Circular. 4587: 1. Retrieved 16 April 2025.
  8. ↑ Marsden, Brian G. (4 May 1988). "X-Ray Nova in Vulpecula". IAU Circular. 4589: 1. Retrieved 16 April 2025.
  9. ↑ Kholopov, P. N.; Samus, N. N.; Kazarovets, B. V.; Frolov, M. S.; Kireeva, N. N. (April 1989). "The 69th Name-List of Variable Stars". Information Bulletin on Variable Stars. 3323: 1–20. Bibcode:1989IBVS.3323....1K. Retrieved 16 April 2025.
  10. ↑ Filippenko, Alexei V.; Matheson, Thomas; Barth, Aaron J. (1995). "A Black Hole in the X-Ray Nova GS 2000+25". Astrophysical Journal Letters. 455 (2): L139. Bibcode:1995ApJ...455L.139F. doi:10.1086/309831. S2CID 123161764.