Newly Discovered Young Planetary Nebulae
Abstract
Potential planetary nebulae are selected from the IRAS point source catalog by their colors. From a list of 600 candidates in the direction of the Galactic bulge, about 20 percent have been confirmed by the presence of radio continuum emission. It is argued that the percentage of PN in the group is much higher, but the others have a radio flux density below the 1 mJy limit imposed by the observations. A substantial fraction of the new PN have very high infrared excesses, indicating that the central star temperature is very low, sometimes less than 13,000 K. The position of these nebulae on the H-R diagram is discussed.
- Publication:
-
From Miras to Planetary Nebulae: Which Path for Stellar Evolution?
- Pub Date:
- 1990
- Bibcode:
- 1990fmpn.coll..381P
- Keywords:
-
- Astronomical Catalogs;
- Galactic Bulge;
- Infrared Astronomy Satellite;
- Planetary Nebulae;
- Point Sources;
- Hertzsprung-Russell Diagram;
- Radio Emission;
- Sky Surveys (Astronomy);
- Stellar Temperature;
- Astrophysics