Spectral types in the Orion OB1 association.
Abstract
Spectral types are derived for 152 stars in the Northwest, Belt, and Outer Sword regions. The classifications show that the following are present: (1) stars above the ZAMS in the O9B3 and the B7-A3 regions; most of these have greater luminosities than class V or are double-lined binaries or peculiar stars; (2) eleven Ap stars of which three are Si rich, two are He rich, five are He poor, and one is Mg poor; (3) four moderate Be stars; (4) only two stars with broad hydrogen lines like the ones that are so prevalent in the Orion Nebula Cluster; (5)14 "sn" stars that have both sharp and broad He I lines, perhaps due to tenuous shells; (6) one classical shell star; (7) several Sirius-type Am stars, although most of the Am stars in the region are foreground stars. Key words: associations-peculiar stars-spectral classification
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- December 1977
- DOI:
- 10.1086/130230
- Bibcode:
- 1977PASP...89..797A
- Keywords:
-
- OB Associations:Spectral Classification;
- Peculiar Stars:Spectral Classification