A NEW CEMP-s RR LYRAE STAR

被引：10

作者：

Kinman, T. D. ^{[1
]}

Aoki, Wako ^{[2
,3
]}

Beers, Timothy C. ^{[1
]}

Brown, Warren R. ^{[4
]}

机构：

[1] Natl Opt Astron Observ, Tucson, AZ 85719 USA

[2] Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan

[3] Grad Univ Adv Studies SOKENDAI, Dept Astron Sci, Sch Phys Sci, Mitaka, Tokyo 1818588, Japan

[4] Smithsonian Astrophys Observ, Cambridge, MA 02138 USA

来源：

ASTROPHYSICAL JOURNAL LETTERS | 2012年 / 755卷 / 01期

基金：

美国国家科学基金会;

关键词：

Galaxy: structure; stars: abundances; stars: horizontal-branch; METAL-POOR STARS; DIGITAL SKY SURVEY; BLUE HORIZONTAL-BRANCH; HAMBURG/ESO SURVEY; CARBON; VARIABLES; HALO; CALIBRATION; KINEMATICS; ABUNDANCES;

D O I：

10.1088/2041-8205/755/1/L18

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We show that SDSS J170733.93+585059.7 (hereafter SDSS J1707+58), previously identified by Aoki and collaborators as a carbon-enhanced metal-poor star (with s-process-element enhancements, CEMP-s), on the assumption that it is a main-sequence turnoff star, is the RR Lyrae star VIII-14 identified by the Lick Astrograph Survey. Revised abundances for SDSS J1707+58 are [Fe/H] = -2.92, [C/Fe] = +2.79, and [Ba/Fe] = +2.83. It is thus one of the most metal-poor RR Lyrae stars known, and has more extreme [C/Fe] and [Ba/Fe] than the only other RR Lyrae star known to have a CEMP-s spectrum (TY Gru). Both stars are Oosterhoff II stars with prograde kinematics, in contrast to stars with [C/Fe] < +0.7, such as KP Cyg and UY CrB, which are disk stars. Twelve other RR Lyrae stars with [C/Fe] >= +0.7 are presented as CEMP candidates for further study.

引用

页数：5

共 47 条

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