Spectrophotometry of Helium Peculiar Stars
Abstract
The mechanism for the spectrum and photometric variations of the magnetic helium peculiar stars is not a settled question. For the cooler stars the primary cause appears to be changes, due to surface inhomogeneities, of Si continuous opacity. For the hotter helium rich stars it appears linked to the helium anomaly and its photosoheric distribution. The connection between the helium weak and helium rich stars is not well understood but appears to be linked to effective temperature on the main sequence via a diffusion mechanism. The purpose of this study is to explore the relation between magnetic field strength and configuration, effective temperature and abundance anomaly using groups of matched He weak and He rich stars. It will, using this sample, also study the relation between the UV variations and the broad continuum features known in the optical at 5200 and 6300 A. The constancy of the stellar flux will also be studied, linking this survey with the OAO-2 and TD-1 studies of a few Si stars. A subsidiary goal is the calibration of high dispersion IUE Spectra obtained in the previous programs (APBSA, HRDPB, and HEESS) for the helium rich stars. The photometric observations made with OAO-2, TD-1, ANS, and the COPERNICUS spectra will all serve as links between the helium rich and weak phenomenology.
- Publication:
-
IUE Proposal
- Pub Date:
- 1983
- Bibcode:
- 1983iue..prop.1531S