Photospheric Abundances of Volatile and Refractory Elements in Planet-Harboring Stars

• Published in: Publications of the Astronomical Society of Japan 2001-12, Vol.53 (6), p.1211-1221
• Main Authors: Takeda, Yoichi, Sato, Bun’ei, Kambe, Eiji, Aoki, Wako, Honda, Satoshi, Kawanomoto, Satoshi, Masuda, Seiji, Izumiura, Hideyuki, Watanabe, Etsuji, Koyano, Hisashi, Maehara, Hideo, Norimoto, Yuji, Okada, Takafumi, Shimizu, Yasuhiro, Uraguchi, Fumihiro, Yanagisawa, Kenshi, Yoshida, Michitoshi, Miyama, Shoken M., Ando, Hiroyasu
• Format: Article
• Language: English
• ISSN: 0004-6264; 2053-051X
• DOI: 10.1093/pasj/53.6.1211

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 $T_\mathrm{c}$ ) 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 $T_\mathrm{c}$ ), which are known to be generally overabundant in those stars with planets, since a $T_\mathrm{c}$ -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., $[\mathrm{X} / \mathrm{Fe}] \simeq 0$ ), 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.