Studies of bipolar nebulae. VII. The exciting star of OH 0739-14 (= OH 231.8+4.2)
Abstract
A spectral classification for the exciting star of the bipolar reflection nebula OH 0739-14, which has also been observed to be an OH/H2O maser source, is obtained from the spectrum of the nebulosity in the range 6000-9000 A. Spectrophotometry of the visible nebula was obtained with the Cassegrain image-tube scanner on the Lick Observatory 3-m telescope at a resolution of approximately 7 A. The red spectrum is found to be distinguished by TiO absorption at the bandheads at 8206, 8303, 8432, 8442 and 8452 A and VO in the 7400 and 7900 A regions. On the basis of the depths of these bandheads and the K I 7699 A and Ca II infrared triplet, OH 0739-14 is determined to be of spectral type M9 III. The underlying star thus represents the coolest known star to occur in a bipolar system.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- June 1981
- DOI:
- 10.1086/130825
- Bibcode:
- 1981PASP...93..288C
- Keywords:
-
- Nebulae;
- Red Giant Stars;
- Stellar Luminosity;
- Stellar Spectra;
- Bipolarity;
- Hydroxyl Emission;
- Infrared Stars;
- Interstellar Masers;
- Late Stars;
- Line Spectra;
- Stellar Spectrophotometry;
- Water Masers;
- Astronomy