The distance to eight X-ray sources derived from Hipparcos observations

Authors
Clark, LL Dolan, JF
Citation
Ll. Clark et Jf. Dolan, The distance to eight X-ray sources derived from Hipparcos observations, ASTRON ASTR, 350(3), 1999, pp. 1085-1088
Citations number
39
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY AND ASTROPHYSICS
ISSN journal
00046361 → ACNP
Volume
350
Issue
3
Year of publication
1999
Pages
1085 - 1088
Database
ISI
SICI code
0004-6361(199910)350:3<1085:TDTEXS>2.0.ZU;2-3
Abstract
The parallaxes of eight galactic X-ray sources measured by Hipparcos are co nsistent with zero in all but two cases, 4U1145-619 (= Cen X-5) and HZ43. T he parallax and proper motion measured for each of the others, including th e Be/neutron star binaries X Per and A0535+26 and the massive X-ray binarie s 4U0900-40, 4U1700-37, and Cyg XR-1, are consistent with their spectroscop ic parallaxes. These results provide no evidence that visible stars in X-ra y binaries have a luminosity that is abnormal for their spectral type.