A NEW HOT DA WHITE-DWARF IN A REGION OF EXCEPTIONALLY LOW H-1 DENSITY

Authors
BARSTOW MA WESEMAEL F HOLBERG JB BUCKLEY DAH STOBIE RS MITTAZ JPD FONTAINE G ROSEN SR DEMERS S LAMONTAGNE R IRWIN MJ BERGERON P KEPLER SO VENNES S
Citation
Ma. Barstow et al., A NEW HOT DA WHITE-DWARF IN A REGION OF EXCEPTIONALLY LOW H-1 DENSITY, Monthly Notices of the Royal Astronomical Society, 267(3), 1994, pp. 647-652
Citations number
31
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Monthly Notices of the Royal Astronomical Society → ACNP
ISSN journal
00358711
Volume
267
Issue
3
Year of publication
1994
Pages
647 - 652
Database
ISI
SICI code
0035-8711(1994)267:3<647:ANHDWI>2.0.ZU;2-Y
Abstract
We report the discovery of the hot DA white dwarf RE 0457 - 281 which has the lowest line-of-sight neutral hydrogen column density yet measu red. The star was found independently by the ROSAT EUV, Montreal-Cambr idge-Tololo and Edinburgh-Cape surveys. With an effective temperature of 60 700 K and very soft EUV spectrum, this white dwarf resembles the well-studied hot DA white dwarf G 191 - B2B. A follow-up observation made using the Voyager 2 UV spectrometer reveals a strong continuum sh ortward of the 912-A Lyman limit from which we deduce that the neutral hydrogen column density is 1.3 x 10(17) atom cm-2