Far-ultravoilet and optical spectrscopy of the detached white dwarf-M binary RE J1629+780

Details Far-ultravoilet and optical spectrscopy of the detached white dwarf-M binary RE J1629+780 Far-ultravoilet and optical spectrscopy of the detached white dwarf-M binary RE J1629+780

Mar 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995pasp..107..232s&link_type=abstract

Astronomical Society of the Pacific, Publications (ISSN 0004-6280), vol. 107, no. 709, p. 232-237

Astronomy and Astrophysics

Astronomy

18

Abundance, Binary Stars, Emission Spectra, Optical Emission Spectroscopy, Radial Velocity, Red Dwarf Stars, Ultraviolet Spectroscopy, White Dwarf Stars, Balmer Series, Data Reduction, Energy Distribution, H Alpha Line, Interstellar Matter, Iue, Lyman Alpha Radiation, Rosat Mission, Spectrum Analysis

Scientific paper

We present optical and far-ultraviolet observations, including IUE high- and low-dispersion spectroscopy, of the (DA2+dM4-5) close binary, RE J1629+780, a very bright ROSAT EUV source. The optical data reveal emission reversals in the cores of the Balmer lines, which vary in strength but reveal no evidence of wavelength shifts reflecting orbital motion, suggesting that the red dwarf and the white dwarf are widely separated. Thus it is unlikely that irradiation plays a dominant role in the activity of the red dwarf. One dramatic increase in the intensity of the H-beta emission strength in the course of one hour indicates that the observed intensity variations are most likely related to flare activity on the red dwarf. Our analysis of Balmer and Lyman alpha features yield Teff = 42,500 +/- 1300 K and log g = 7.6 +/- 0.3 for the DA2 white dwarf, which is consistent with the overall 900 to 3200 A energy distribution derived from Voyager and IUE low-dispersion spectra. Our analysis of three IUE echelle spectra reveal numerous lines of interstellar origin. Using a total of 13 interstellar matter (ISM) features we find a mean radial velocity of -13.57 +/- 1.66 km/s for the interstellar features. However, we found no evidence of trace metal absorbers levitated or accreted in the white-dwarf photosphere nor any evidence of circumstellar or wind features. We estimate a lower limit hydrogen layer mass of 2.1 x 10-15 solar mass for a stratified atmosphere based upon the nondetection of He II (1640). Tighter constraints on the helium abundance and the hydrogen layer mass, from EUV and X-ray data, are presented for both homogeneous and stratified atmospheric configurations.

Affiliated with

Also associated with

No associations

Rating

Far-ultravoilet and optical spectrscopy of the detached white dwarf-M binary RE J1629+780 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 Far-ultravoilet and optical spectrscopy of the detached white dwarf-M binary RE J1629+780, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Far-ultravoilet and optical spectrscopy of the detached white dwarf-M binary RE J1629+780 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-849221