Dynamical Mass Determinations for the White Dwarf Components of HZ 9 and Case 1
Abstract
Radial-velocity curves for both components of the short-period, white dwarf M dwarf binary systems Case 1 and HZ 9 have been determined from 1-Å-resolution spectra obtained at the MMT. The new data have been used to estimate masses for the white dwarfs, yielding M = 0.38 M_sun; for the Case 1 DA and M = 0.51 M_sun; for the HZ 9 DA, with 1 σ uncertainties of about 0.1 M_sun;. Both M dwarfs show significant variability in their chromospheric emission-line strengths. Accretion of the dM wind onto the white dwarfs in these systems should produce detectable metal absorption lines in the UV, as has been observed recently with IUE spectra of Feige 24.
- Publication:
-
The Astronomical Journal
- Pub Date:
- October 1987
- DOI:
- 10.1086/114533
- Bibcode:
- 1987AJ.....94..996S
- Keywords:
-
- Astronomical Spectroscopy;
- Iue;
- Radial Velocity;
- Stellar Mass;
- White Dwarf Stars;
- Binary Stars;
- Emission Spectra;
- Stellar Winds;
- Astrophysics;
- STARS: WHITE DWARFS;
- STARS: SUBDWARFS