The Unusual Pre--Main-Sequence Star VY Tauri
Abstract
VY Tau is a pre-main-sequence star in the Taurus-Auriga clouds which differs from conventional T Tauri stars in two respects: (1) its light curve, featuring sporadic outbursts from about B = 14 to 11-12 interspersed with many years of inactivity; (2) its remarkable emission spectrum, dominated by low-level lines of Fe I, Si I, Mg I with an excitation temperature of about 2700 K. Higher excitation species such as Fe II and the Balmer lines are relatively weak. An MO V absorption spectrum is present when the star is inactive. Some very tentative models that might account for the unusual spectrum and photometric behavior are offered. Since there is no significant infrared excess, an interpretation in terms of an accretion or passive reprocessing disk is not called for. The discussion is based on old spectroscopic material, largely collected prior to 1972, when the star was last active. There is need for a modern reinvestigation at all wavelengths, particularly when the activity resumes.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1990
- DOI:
- 10.1086/169151
- Bibcode:
- 1990ApJ...360..639H
- Keywords:
-
- Pre-Main Sequence Stars;
- Stellar Spectra;
- Absorption Spectra;
- Balmer Series;
- Emission Spectra;
- Light Curve;
- T Tauri Stars;
- Astrophysics;
- STARS: EMISSION-LINE;
- STARS: INDIVIDUAL CONSTELLATION NAME: VY TAURI;
- STARS: PRE--MAIN-SEQUENCE