Discovery of fast optical activity in the X-ray source GX 339-4.
Abstract
The paper presents the first results of fast optical photometry of the GX 339-4 counterpart obtained in late May 1981 when the object was found in an unusually bright state (V=15.4). The optical flux displays 20 second quasi-oscillations of 30-40% full amplitude together with very short time scale activity. Flares as short as 10-20 milliseconds are observed, during which the flux can be increased by a factor up to 5. The overall optical time behavior is shown to be very similar to the X-ray time behaviour of Cyg X-1. Optical flares are likely to come from the hot inner part of the accretion disc. Possible interpretations of the 20 second quasi-oscillations are discussed.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1982
- Bibcode:
- 1982A&A...109L...1M
- Keywords:
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- Astronomical Photometry;
- Time Response;
- X Ray Sources;
- Flares;
- Radiant Flux Density;
- X Ray Astronomy;
- Astronomy