The Accreting White Dwarf in the Close Binary EUVE J1016-053

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

13

Stars: Abundances, Stars: Binaries: Close, Stars: Individual Alphanumeric: Euve J1016-053, Ultraviolet: Stars

Scientific paper

The hot white dwarf in the close binary EUVE J1016-053 (=RE 1016-053) has been classified as a DAO white dwarf; its mixed H/He composition has been attributed to steady accretion from the close red dwarf companion. We have obtained extreme-ultraviolet (EUV) photometric and spectroscopic observations of EUVE J1016-053 with the Extreme Ultraviolet Explorer (EUVE). We report the discovery of a ~30% EUV flux variation over a period of 57.3 minutes, which we attribute to surface abundance inhomogeneities modulated over the stellar rotation period, Prot. The EUVE spectrum shows the effect of heavy-element opacities on the white dwarf EUV energy distribution. Spectral synthesis including trace opacities of helium and a group of heavy elements (C, N, O, Si, S, Fe) in the otherwise hydrogen-rich atmosphere constrains abundances to Y/Ysolar = Z/Zsolar = 2 x 10-3, in support of a simple accretion model. The low surface-averaged helium abundance measured in the white dwarf atmosphere limits the accretion rate to between 10-19 and 10-18 Msolar yr-1, i.e., much lower than the Bondi-Hoyle accretion rate, which is of the same order as the red dwarf mass-loss rate (>=10-14 Msolar yr-1), therefore invalidating a simple wind-accretion model. We speculate that weak mass loss from the white dwarf or interaction with a magnetosphere may inhibit accretion onto the white dwarf. Accretion of heavy elements may also be restricted to smaller areas, possibly correlating to magnetic poles.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The Accreting White Dwarf in the Close Binary EUVE J1016-053 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Accreting White Dwarf in the Close Binary EUVE J1016-053, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Accreting White Dwarf in the Close Binary EUVE J1016-053 will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1472997

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.