The fate of the earth in the red giant envelope of the sun
Abstract
A number of hydrostatic models may be found in the literature for red giants whose main sequence progenitors are solar-like stars. Of those models some provide stellar radii just in excess of the earth-sun distance. For such a situation, if drag forces, wind ram pressure and vaporization are not too severe at the low temperature, low density surface of the solar red giant envelope, one might expect the earth to survive through the planetary nebula phase, eventually to orbit the relic solar white dwarf. Employing a 30 zone red giant model, the earth orbital decay timescale neglecting ablation/vaporization is determined to be of the order of 200 years, rendering earth survival impossible. The effects of ablation/vaporization processes are found to increase the ballistic coefficient of earth, thereby setting the 200 year decay timescale as an upper limit.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1987
- Bibcode:
- 1987A&A...178..283G
- Keywords:
-
- Earth (Planet);
- Red Giant Stars;
- Stellar Envelopes;
- Sun;
- Ablation;
- Drag;
- Orbit Decay;
- Stellar Evolution;
- Stellar Models;
- Vaporizing;
- Astrophysics