The First Hypervelocity Star from the LAMOST Survey
Abstract
We report the first hypervelocity star (HVS) discovered from the LAMOST spectroscopic survey. It is a B-type star with a heliocentric radial velocity about 620 km/s, which projects to a Galactocentric radial velocity component of ~477 km/s. With a heliocentric distance of ~13 kpc and an apparent magnitude of ~13 mag, it is the nearest bright HVS currently known. With a mass of ~9Msun, it is one of the three most massive HVSs discovered so far. The star is clustered on the sky with many other known HVSs, with the position suggesting a possible connection to Galactic center structures. With the current poorly-determined proper motion, a Galactic center origin of this HVS remains consistent with the data at the 1sigma level, while a disk run-away origin cannot be excluded. We discuss the potential of the LAMOST survey to discover a large statistical sample of HVSs of different types.
Cite
@article{arxiv.1401.5063,
title = {The First Hypervelocity Star from the LAMOST Survey},
author = {Zheng Zheng and Jeffrey L. Carlin and Timothy C. Beers and Licai Deng and Carl J. Grillmair and Puragra Guhathakurta and Sebastien Lepine and Heidi Jo Newberg and Brian Yanny and Haotong Zhang and Chao Liu and Ge Jin and Yong Zhang},
journal= {arXiv preprint arXiv:1401.5063},
year = {2015}
}
Comments
5 pages, 5 figures, accepted for publication in ApJL, updated contour plot for the ejection positions after correcting a mistake in the calculation