Evidence of rocky planetesimals orbiting two Hyades stars
Evidence of rocky planetesimals orbiting two Hyades stars
复制标题
围绕两颗毕宿星运行的岩石微星的证据
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
D. Koester
中科院分区：
文献类型：
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作者：
J. Farihi;B. Gansicke;D. Koester
毕星团是距离最近的疏散星团，相对年轻，包含大量A型恒星；其已知的年龄、距离和金属丰度使其成为研究2-3 M⊙恒星周围行星系统的理想地点，其年代类似于晚期的重轰击。哈勃太空望远镜的远紫外线光谱强烈表明，在两个Hyad残留物中，持续的外部金属污染。对于两颗恒星的持续积累，污染物质的对数 [n(Si)/n(C)]>；0.2，比球粒陨石更缺乏碳，因此是岩石。这些数据与一张图片相一致，在毕马座的两颗主序A型恒星周围形成了岩石小行星和小行星，它们的白矮星后代带有伤疤。这些通过金属污染进行的探测被证明相当于LIR/L*∼10−6在恒星陆地区的红外过量。
The Hyades is the nearest open cluster, relatively young and containing numerous A-type stars; its known age, distance, and metallicity make it an ideal site to study planetary systems around 2–3 M⊙ stars at an epoch similar to the late heavy bombardment. Hubble Space Telescope far-ultraviolet spectroscopy strongly suggests ongoing, external metal pollution in two remnant Hyads. For ongoing accretion in both stars, the polluting material has log [n(Si)/n(C)] > 0.2, is more carbon deficient than chondritic meteorites and is thus rocky. These data are consistent with a picture where rocky planetesimals and small planets have formed in the Hyades around two main-sequence A-type stars, whose white dwarf descendants bear the scars. These detections via metal pollution are shown to be equivalent to infrared excesses of LIR/L* ∼ 10−6 in the terrestrial zone of the stars.