PERIODIC UV MODULATION OF X1850-087 - A DOUBLE DEGENERATE BINARY IN THE GLOBULAR-CLUSTER NGC-6712

Authors
HOMER L CHARLES PA NAYLOR T VANPARADIJS J AURIERE M KOCHMIRAMOND L
Citation
L. Homer et al., PERIODIC UV MODULATION OF X1850-087 - A DOUBLE DEGENERATE BINARY IN THE GLOBULAR-CLUSTER NGC-6712, Monthly Notices of the Royal Astronomical Society, 282(3), 1996, pp. 37-46
Citations number
56
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Monthly Notices of the Royal Astronomical Society → ACNP
ISSN journal
00358711
Volume
282
Issue
3
Year of publication
1996
Pages
37 - 46
Database
ISI
SICI code
0035-8711(1996)282:3<37:PUMOX->2.0.ZU;2-2
Abstract
We report the discovery with the Hubble Space Telescope (HST) of a sho rt-period (20.6 min) UV modulation in X1850-087, the luminous X-ray so urce in the globular cluster NGC 6712. The low-amplitude modulation (0 .044 +/- 0.007 mag) is not detected in archival X-ray observations wit h EXOSAT. We compare the properties of X1850 - 087 with the Ii-min bin ary X1820 - 303 and identify the modulation as the orbital period, whi ch requires the mass-losing companion to be degenerate and of low mass (0.04 M(.)).