Dust and gas near the Pleiades.
Abstract
Observations of molecular hydrogen are used to argue that the dust toward 20 Tau in the Pleiades is in front of that star and that the reflection nebula NGC 1432 is optically thin. The H2 destruction rate at the surface of the cloud toward 20 Tau is estimated along with the distance of the cloud from the star, the thickness of the cloud, and the optical thickness of the reflection nebula. A dilution coefficient for the cloud near the star is computed which is about 100 times higher than the value for the average interstellar radiation field. Possible origins are considered for the large amount of CH(+) observed toward 20 Tau.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1977
- DOI:
- 10.1086/155730
- Bibcode:
- 1977ApJ...218..749J
- Keywords:
-
- Cosmic Dust;
- Hydrogen Clouds;
- Interstellar Gas;
- Nebulae;
- Pleiades Cluster;
- Astronomical Models;
- Hydrocarbons;
- Interstellar Matter;
- Optical Pumping;
- Optical Thickness;
- Polarization (Waves);
- Astrophysics