Abundances of volatile elements in post-AGB candidates

作者：Takeda Yoichi^*; Taguchi Hikaru; Yoshioka Kazuo; Hashimoto Osamu; Aikawa Toshiki; Kawanomoto Satoshi

来源：Publications of the Astronomical Society of Japan, 2007, 59(6): 1127-1140.

• stars : abundances
• stars : AGB and post-AGB
• stars : atmospheres
• stars : evolution
• stars : individual (HD 112374, HD 148743, HD 161796, HD 163506, HD 187203)

A detailed non-LTE study on the abundances of C, N, O, S, and Zn was carried out for five F-G supergiants of suspected post-AGB candidates with IR excesses (HD 112374, HD 148743, HD 161796, HD 163506, and HD 187203), since these volatile elements can provide the key to inferring the original metallicity as well as an evolution-induced change due to mixing, given that they are free from depletion caused by dust-gas separation. The extent of separation-induced depletion in Fe, estimated by comparing with Zn, turned out to be rather moderate (less than or similar to several tenths dex). The characteristics of the C, N, and O abundances do not appear to be very different from the case of the first dredge-up in normal supergiants (decreased C and enriched N due to the first dredge-up); thus, the specific anomaly related to an advanced post-AGB stage so far reported (such as elevated C and O) could not be clearly confirmed.

• 出版日期2007
• 单位中国科学院国家天文台