Publication Date:
2011-08-16
Description:
The MIT X-ray detectors aboard the OSO-7 spacecraft viewed Hercules X-1 from November 14 to 24, 1972. X-ray turn-on in the 35-day cycle was observed to occur between phases 0.67 and 0.70 (November 18.64-18.70). A significant decrease in the X-ray intensity occurred near mid-orbital phase, approximately 1.5 days after X-ray turn-on. Using the 1-6 keV data obtained during the 35-day off state, we conclude that if the optical light curve is due to heating of the large star by a blackbody source of soft X-rays, then the source must be large (radius greater than 5,000 km) and cool (temperature (kT) less than 90 eV). During one eclipse period (November 20.8-21.0) we find evidence for 1-6 keV X-ray emission.
Keywords:
SPACE SCIENCES
Type:
Astrophysical Journal; 188; Feb. 15
Format:
text
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