Further optical observations of HZ Herculis.
Abstract
Optical observations of HZ Her made in the spring and summer of 1973 are presented. Some of the observations are practically coincident with estimated turn-on times for Her X-1 and others are simultaneous with X-ray observations made using the Copernicus satellite. Eight magnitudes were also measured from old plates for the epoch 1953-60; these measurements confirm the long-term variations for that epoch reported by Jones, Forman, and Liller (1973). An interesting theoretical explanation by Fabian, Pringle, and Rees (1973) for the persistence of large optical variations throughout the 35-day X-ray period is ruled out by simultaneous UHURU (X-ray) and Wise Observatory (optical) observations.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- February 1975
- DOI:
- 10.1086/129736
- Bibcode:
- 1975PASP...87..141B
- Keywords:
-
- Binary Stars;
- Light Curve;
- Stellar Luminosity;
- X Ray Astronomy;
- X Ray Stars;
- Astronomical Photometry;
- Error Analysis;
- Spaceborne Astronomy;
- Uhuru Satellite;
- Variable Stars;
- Astrophysics