Do X-Ray Sporadic Flare-ups of GS 2023+338 (=V404 Cyg) Relate to Orbital Motion ?
Abstract
An X-ray nova, GS 2023+338 (=V404 Cyg), was observed to exhibit two successive X-ray flare-ups on May 23 and May 30 in 1989 during observations with the Large Area Proportional Counter on board the Ginga satellite. Each flare-up comprised several sporadic bursts, the intensity of which varied by a factor of 40--100 for 120--160 min. The interval of two successive flare-ups was just the orbital period of 6.5 d; both flare-ups occurred at an orbital phase of 0.294--0.311. In this case, an orbital phase of 0.0 corresponds to the superior conjunction of the compact star in the 6.5-day orbital motion of the X-ray binary. Among seven snap-shot observations with the All Sky Monitor during the early stage of the X-ray nova, one data point at an orbital phase of 0.2 on May 23 showed a high X-ray intensity of 8 count s(-1) cm(-2) , whereas the others did not. These results suggest that sporadic flare-ups were likely to occur around orbital phases of 0.2--0.35 during the early stage of an X-ray nova. If so, they indicate the existence of a trigger mechanism of sporadic flare-ups which originate from the orbital motion, in addition to the mechanisms of the so-called outburst of the X-ray nova.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- December 1994
- Bibcode:
- 1994PASJ...46..677T
- Keywords:
-
- Orbital Mechanics;
- Stellar Flares;
- Stellar Mass Accretion;
- Stellar Orbits;
- X Ray Binaries;
- Accretion Disks;
- Black Holes (Astronomy);
- Ginga Satellite;
- Mass Transfer;
- Sky Surveys (Astronomy);
- Astrophysics;
- BLACK HOLES;
- STARS: BINARIES;
- STARS: INDIVIDUAL (V404 CYG;
- GS 2023+338);
- STARS: NOVAE;
- X-RAYS: BINARIES