Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Further x-ray observations of Hercules X-1 from Uhuru

Journal Article · · Astrophys. J., v. 184, no. 1, pp. 227-236
OSTI ID:4317352
Recent data are presented concerning the X-ray source Hercules X-1. Details of the 1.24-second pulse shape and its variability are shown. The 1.24- second period is observed to decrease with time, with an overall change of 4.5 mu s between 1972 January and July. The X-ray intensity shows regular on states lasting 11 or 12 days followed by 24-day off states. While ihe source turu-on is not strictly periedic, the shape of the on state can be used to determine a period of 34.88 plus or minus 0.12 days for this cycle. The source turn-ons are found to only occur at one of two well-defined phases in the 1.7-day orbit. In addition to the regular 1.7-day eclipses, regular dips in the X-ray intensity are seen, whose occurrence is related to the orbital phase. These dips are interpreted as absorption by gas in thc system. (auth)
Research Organization:
American Science and Engineering, Inc., Cambridge, Massachusetts
NSA Number:
NSA-29-021931
OSTI ID:
4317352
Journal Information:
Astrophys. J., v. 184, no. 1, pp. 227-236, Journal Name: Astrophys. J., v. 184, no. 1, pp. 227-236; ISSN ASJOA
Country of Publication:
United States
Language:
English

Similar Records

Uhuru observations of Hercules X-1 during the low state of the 35-day cycle
Journal Article · Sun Oct 31 23:00:00 EST 1976 · Astrophys. J., Lett.; (United States) · OSTI ID:7245391

An analysis of the precession of the accretion disk of Hercules X-1
Journal Article · Mon May 01 00:00:00 EDT 1989 · Astrophys. J.; (United States) · OSTI ID:5856491

Hard x-ray spectrum of Hercules X-1
Journal Article · Mon Jul 23 00:00:00 EDT 1973 · Nature (London) Phys. Sci., v. 244, no. 134, pp. 59-60 · OSTI ID:4433543