Helium line profile variations in the DAB white dwarf HS 0209+0832.

Details Helium line profile variations in the DAB white dwarf HS 0209+0832. Helium line profile variations in the DAB white dwarf HS 0209+0832.

Aug 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997a%26a...324l..53h&link_type=abstract

Astronomy and Astrophysics, v.324, p.L53-L56

Other

19

Stars: White Dwarfs, Stars: Atmospheres, Stars: Abundances, Stars: Variables: Other, Stars: Individual: Hs 0209+0832, Diffusion

Scientific paper

HS 0209+0832, the only white dwarf known to show helium lines in the DB gap region, is reported to display profile variations of helium lines. A quantitative spectroscopic analysis using NLTE model atmospheres reveals that the line profile variations are consistent with a constant T_eff_=36100K and log g=7.91 but with a varying helium abundance. It decreased from a high abundance state (He/H=0.012, by number) by a factor of 2 to 3 in 1995 and recovered back to the high abundance state in 1996. The previously suggested possibility that HS0209+0832 is a composite spectrum (DA+DB) object is ruled out by the spectral analysis. Hence HS0209+0832 is the first DAB star to be unambigously near the middle of the DB gap and appears to be explainable by a homogeneous He/H atmosphere with the helium abundance lower by a factor of 2-3 in one observation.

Affiliated with

Also associated with

No associations

Rating

Helium line profile variations in the DAB white dwarf HS 0209+0832. 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 Helium line profile variations in the DAB white dwarf HS 0209+0832., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Helium line profile variations in the DAB white dwarf HS 0209+0832. will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1877788