Circinus X-1
Abstract
L. J. Kaluzienski, S. S. Holt, E. A. Boldt and P. J. Serlemitsos, Goddard Space Flight Center, report: "Analysis of recent data from Cir X-1 (3U 1516-56) with the Ariel 5 all-sky monitor indicates the presence of a source modulation of period 16.59 +/- 0.06 days. About ten cycles were observed during Oct. 1975-Mar. 1976, a declining trend over the last few peaks indicating a gradual return to the low-level emission (< 0.1 times the Crab) that was characteristic of the source before Oct. 1975. The transition from highest to lowest emission (a reduction by a factor of >~ 20) within the 16.59-day period occurs over a timescale of one orbit (<~ 1.5 hours) and may imply an eclipse origin. The epoch of this transition is 1976 Feb. 2.36 +/- 0.07 UT."
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- April 1976
- Bibcode:
- 1976IAUC.2939....3K