Photospheric Abundances of Volatile and Refractory Elements in Planet-Harboring Stars
Abstract
By using the high-dispersion spectra of 14 bright planet-harboring stars (along with 4 reference stars) observed with the new coudé echelle spectrograph at Okayama Astrophysical Observatory, we investigated the abundances of volatile elements (C, N, O, S, Zn; low condensation temperature Tc) in order to examine whether these show any significant difference compared to the abundances of other refractory elements (Si, Ti, V, Fe, Co, Ni; high Tc), which are known to be generally overabundant in those stars with planets, since a Tc-dependence is expected if the cause of such a metal-richness is due to the accretion of solid planetesimals onto the host star. We found, however, that all elements which we studied behave themselves quite similarly to Fe (i.e., [X /Fe] ~= 0), even for the case of volatile elements. This may suggest that the enhanced metallicity in those planet-bearing stars is not so much an acquired character (by accretion of rocky material) as rather primordial.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- December 2001
- DOI:
- 10.1093/pasj/53.6.1211
- arXiv:
- arXiv:astro-ph/0109245
- Bibcode:
- 2001PASJ...53.1211T
- Keywords:
-
- STARS: ABUNDANCES;
- STARS: ATMOSPHERES;
- STARS: PLANETARY SYSTEMS;
- Astrophysics
- E-Print:
- 22 pages, 8 figures, to appear in PASJ