EXO 0748-676
Abstract
A. N. Parmar, N. E. White, P. Giommi and F. Haberl, EXOSAT Observatory, telex: "EXOSAT discovered a bright (0.03 Crab) transient x-ray source on Feb. 15. The preliminary position is R.A. = 07h48m24s5, Decl. = -67deg37'23" (equinox 1950.0), with an error radius of 15". The source shows bursts, irregular intensity dips and periodic total eclipses. The first observed eclipse was centered on Feb. 15d01h46m57s UT (barycentric), with a duration of 500 s. The eclipses recur with a period of 3.824 +/- 0.001 hr. The intensity dips occur between phases 0.5 and 1.0, where 0.0 is the center of eclipse. Further EXOSAT observations are planned to follow the evolution of the outburst, and an optical search of the error region is strongly urged. A further observation on Feb. 19 showed the source to be at a similar intensity level." H. Pedersen, European Southern Observatory; and M. Mayor, Geneva Observatory, using CCD photometry obtained at the 1.54-m Danish telescope at La Silla, have identified EXO 0748-676 with a blue variable star at a position consistent with that of the x-ray source. At maximum V = 16.9, B-V = +0.1. The source was followed during Feb. 19d01h22m-19d06h41m UT using a time resolution of 5 min. During this period there were two eclipses, and the times fit the x-ray ephemeris; the amplitude of variability is 0.6 mag.
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- February 1985
- Bibcode:
- 1985IAUC.4039....1P