Cygnus X-1
Abstract
S. S. Holt, L. J. Kaluzienski, E. A. Boldt and P. J. Serlemitsos, Goddard Space Flight Center, report that the present Cyg X-1 increase (IAUC 2863) shows no sign of decay after more than one month of continuous interrogation by the Ariel 5 all-sky monitor. Previous increases in May and September did not last much longer than one week, and the x-ray intensity started decaying after a few days. Cyg X-1 may therefore have returned to a long-term high-intensity level similar to that prior to the 1971 transition. Its present average intensity is approximately 1.5 times that of the Crab Nebula in the energy range 3-6 keV.
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- December 1975
- Bibcode:
- 1975IAUC.2879....2H