Discovery of a Bright X-Ray Nova, GS 2000+25
Abstract
The discovery of the X-ray transient, GS 2000+25, which appeared in the constellation Vulpecula on April 23, 1988 with the All Sky Monitor (ASM) on board the Ginga satellite is reported. The maximum observed intensity was about 12 Crab (1-6 keV). Two stars in the X-ray error box appeared to increase in brightness from the epoch of the Palomar Observatory Sky Survey; one of these was confirmed to be the counterpart by optical spectra and radio measurements. The X-ray spectrum and light curve during the decay phase shows that it belongs to a class of ultrasoft sources which include black hole candidates like A0620-00. A detailed comparison with A0620-00 supports the identification of GS 2000+25 as a possible new black hole candidate.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1989
- DOI:
- 10.1086/185383
- Bibcode:
- 1989ApJ...337L..81T
- Keywords:
-
- Black Holes (Astronomy);
- Light Curve;
- Novae;
- X Ray Stars;
- Japanese Spacecraft;
- Sky Surveys (Astronomy);
- X Ray Spectra;
- Astrophysics;
- BLACK HOLES;
- STARS: NOVAE;
- STARS: X-RAYS