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arXiv · 0911.3177

A Star in the M31 Giant Stream: the Highest Negative Stellar Velocity Known

N. Caldwell·H. Morrison·S. J. Kenyon·R. Schiavon·P. Harding·J. A. Rose
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Abstract

We report on a single star, B030D, observed as part of a large survey of objects in M31, which has the unusual radial velocity of -780 km/s. Based on details of its spectrum, we find that the star is an F supergiant, with a circumstellar shell. The evolutionary status of the star could be one of a post-mainsequence close binary, a symbiotic nova, or less likely, a post-AGB star, which additional observations could help sort out. Membership of the star in the Andromeda Giant Stream can explain its highly negative velocity.

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N. Caldwell, H. Morrison, S. J. Kenyon, R. Schiavon, P. Harding, J. A. Rose. 2009-11-16. A Star in the M31 Giant Stream: the Highest Negative Stellar Velocity Known. https://doi.org/10.1088/0004-6256/139/2/372

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