ACCURATE PERIOD DETERMINATION OF AN ECLIPSING BINARY-X-RAY SOURCE IN M33

Authors
SCHULMAN E BREGMAN JN COLLURA A REALE F PERES G
Citation
E. Schulman et al., ACCURATE PERIOD DETERMINATION OF AN ECLIPSING BINARY-X-RAY SOURCE IN M33, The Astrophysical journal, 418(2), 1993, pp. 120000067-120000070
Citations number
14
Categorie Soggetti
Astronomy & Astrophysics
Journal title
The Astrophysical journal → ACNP
ISSN journal
0004637X
Volume
418
Issue
2
Year of publication
1993
Part
2
Pages
120000067 - 120000070
Database
ISI
SICI code
0004-637X(1993)418:2<120000067:APDOAE>2.0.ZU;2-#
Abstract
We have analyzed the time variability of one of the X-ray sources in M 33 observed by both the ROSAT and Einstein Observatory telescopes. The light curve of M33 X-7 exhibits a variability pattern of high and low states, suggesting an eclipsing binary X-ray source. The data suggest a binary period P = 1.78572 days (very close to that of Her X-1) and an eclipse duration of approximately 0.4 days. The low phase lasts abo ut one-fourth of the period as in Cen X-3.