The Masses Of The B-Stars In The High Galactic Latitude Eclipsing Binary IT Lib

Abstract

A number of blue stars which appear to be similar to Population I B-stars in the star forming regions of the galactic disk are found more than 1 kpc from the galactic plane. Uncertainties about the true distances and masses of these high latitude B-stars has fueled a debate as to their origin and evolutionary status. The eclipsing binary IT Lib is composed of two B-stars, is approximately one kiloparsec above the galactic plane, and is moving back toward the plane. Observations of the light and velocity curves presented here lead to the conclusion that the B-stars in this system are massive young main-sequence stars. While there are several possible explanations, it appears most plausible that the IT Lib system formed in the disk about 30 million years ago and was ejected on a trajectory taking it to its present position.

arXiv comment26 pages, 3 figures, accepted for publication in the PASP (January 2003)

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Cited by in corpus (7)

• Runaway and hypervelocity stars in the Galactic halo: Binary rejuvenation and triple disruption
• Ejection velocities of high Galactic latitude runaway stars
• The Origins and Evolutionary Status of B Stars Found Far From the Galactic Plane II: Kinematics and Full Sample Analysis
• The Origins and Evolutionary Status of B Stars Found Far From the Galactic Plane I: Composition and Spectral Features
• The Origin of B-Type Runaway Stars: Non-LTE Abundances as a Diagnostic
• The Transformative Journey of HD 93521
• Mass Transfer as an Explanation for the Lifetime-Travel Time Discrepancy in IT Librae