On the variability of four yellow supergiants - possible protoplanetary objects.
Abstract
Photoelectric UBV observations of four supergiants with a large IR excess (IRAS 18095 + 2704, IRAS 19386 + 0155, and SAO 34504), possible progenitors of planetary nebulae, are presented. All of them exhibited brightness variations with amplitudes from 0.2 to 0.5 m over the period 1990-1992.
- Publication:
-
Astronomy Letters
- Pub Date:
- May 1993
- Bibcode:
- 1993AstL...19..169A
- Keywords:
-
- Brightness Distribution;
- Hertzsprung-Russell Diagram;
- Protoplanets;
- Supergiant Stars;
- Ubv Spectra;
- Astronomical Photometry;
- Planetary Nebulae;
- Variability;
- Astrophysics