Infrared Stellar Surveys and Index Sequences
Abstract
A discussion of spectral radiation and photometry is followed by the development of the use of the outstanding infrared indices of long-period variables and "infrared stars" as a method for the detection and classification of these objects. The reddest stars in eight fields of 5° sq. deg. have been catalogued and charted. No infrared indices (visual to 8500 A) have been found greater than about 9 or io mag., which seems to be a critical limit, since a considerable fraction of the sky-about 3030 sq. deg.-has been covered to the eighth magnitude (for Ao stars). New red vari- ables are among the stars listed, most of which are probably giants. No proper motions have been noted for the brighter ones by superposition of the plates. Four intrinsically faint (visually) proper-motion stars, Wolf 359, Mv 16.5; 02 Eridani C, M~ 12.3; Bar- nard's star, M~ 13.7; and CC 1382, M~ ii.8, have been found to have infrared indices of 5, 2.8, 3.0 and 2.5 mag., respectively. With one possible exception, no infrared Algol stars have been found on a number of survey plates examined for this purpose. Attention is called to certain other stars which may be suspected of duplicity, there being possible infrared companions
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1937
- DOI:
- 10.1086/143885
- Bibcode:
- 1937ApJ....86..509H