GHRS Spectra of the Active Chromosphere Binary V711 Tau (HR 1099)
Abstract
During a multiwavelength campaign in September of 1993 a unique array of telescopes was directed at the chromospherically-active binary system V711 Tau (HR 1099) in an effort to determine fundamental properties of a late-type stellar atmosphere from the photosphere to the corona. Observations of the RS CVn system V711 Tau were obtained with the HST, IUE, VLA, and EUVE observatories. In addition, ground-based optical spectroscopy and photometry were obtained with the APT in Phoenix and at Penn State's Black Moshannon Observatory. We present preliminary results from GHRS observations obtained at 5 phases over 2.5 stellar rotations. GHRS spectra of Mg II h & k (2796, 2830 Angstroms)\ and the C IV doublet (1548,1550 Angstroms)\ are used to probe the chromosphere and transition regions of the K1 IV star, while electron density diagnostics are extracted from the Si III] (1892 Angstroms)\ and C III] (1909 Angstroms)\ intersystem lines. Additional spectra of the 2600 Angstroms region and H I Lyman-alpha spectral regions were obtained at one quadrature phase. Although phase coverage is poor, we are able to extract limited information on temporal and/or spatial variability of the system. Changes in line flux and profile shape are observed in several lines including a variation of approximately 60% in the Si III]/C III] ratio. Finally, since V711 Tau has been observed extensively by IUE over the past 16 years, the HST data provide a high resolution benchmark for this larger body of data.
- Publication:
-
American Astronomical Society Meeting Abstracts #184
- Pub Date:
- May 1994
- Bibcode:
- 1994AAS...184.0514D