Infalling Planetesimals in Young Star Clusters

派：皮拉科夫斯基博士。印第安纳大学授予Pilachowski基金，利用最近在年轻恒星系统中发现的“坠落蒸发体”(FEBS)来研究行星形成的时间尺度。FEB是一种行星体，其轨道被新形成的行星扰动。这些行星体要么被从行星系统中抛出，要么被送入撞击或擦过中央恒星的轨道。在恒星附近，行星体被加热并转化为气体，通过它们的瞬时光谱吸收特征可以被探测到。FEBS提供了恒星系统中行星和行星体的直接证据，也提供了关于该系统的动力学和行星体组成的信息。对具有明确质量和年龄的年轻恒星样本的FEBS观测可能会限制行星形成的时间尺度和/或轨道迁移的机制。皮拉科夫斯基博士将研究年轻星团中的B晚期和A早期矮星，这些恒星的年龄从几百万年到3000万年不等，以探索行星形成和轨道迁移可能导致小行星从年轻太阳系中消失的时间尺度。这些恒星将使用3.5米的威斯康星-印第安纳-耶鲁-NOAO(WIYN)望远镜和多目标光谱仪进行光谱监测。PI将包括研究生和本科生参与这项工作，并预计这项关于太阳系外行星系统中的“彗星”的研究可能会引起广泛的公众兴趣，并激发孩子们的想象力。***

PI: PilachowskiDr. Pilachowski is awarded funds at Indiana University to use the recently discovered "falling evaporative bodies" (FEBs) in young star systems to study the timescale for the formation of planets. FEBs are planetesimals whose orbits are perturbed by newly formed planets. The planetesimals are either ejected from the planetary system or sent inward on orbits that impact or graze the central star. Near the star, the planetesimals are heated and turned to gas, and can be detected by their transient spectral absorption features. The FEBs offer direct evidence of planets and planetesimals in the star system, and also provide information about the dynamics of the system and the composition of the planetesimals. Observations of FEBs in a sample of young stars with well-defined masses and ages may constrain the timescale of planet formation and/or the mechanism of orbital migration. Dr. Pilachowski will examine late B and early A dwarf stars in young star clusters ranging in age from a few million years up to 30 million years to explore the timescales over which planetesimals may be cleared out of young solar systems by the formation of planets and by orbital migration. The stars will be monitored spectroscopically using the 3.5-m Wisconsin-Indiana-Yale-NOAO (WIYN) telescope and multi-object spectrograph. The PI will involve both graduate and undergraduate students in the work, and expects that this study of "comets" in extra-solar planetary systems is likely to attract broad public interest and to fire the imaginations of children. ***