# Summary of K2 Program GO15087

Title: The Runaway Binary IT Librae

PI: Gies, Douglas Russell (Georgia State University)
CoIs: 

The eclipsing binary IT Lib is one of only three known 
eclipsing binaries that consist of massive B-type stars, 
yet are found far from the disk of the Galaxy.   
The best explanation may involve ejection from a 
birthplace in the Galactic plane through dynamical 
interactions with other stars or through a supernova 
explosion of a prior companion.  However, in the case of 
IT Lib, its current position and velocity imply that 
ejection occurred some 33 million years ago, longer than 
the estimated main-sequence lifetime of the primary of 
22 million years. We need to re-assess the masses and 
other properties of the binary in order to try to 
resolve this inconsistency.  

IT Lib will be within the Kepler K2 field of view during 
Campaign 15, and this offers us a remarkable opportunity to 
obtain an extremely high quality light curve.  Furthermore, 
the residuals from the binary light curve will also 
demonstrate whether either star is a pulsator, which would 
enable asteroseismology studies of the interiors. 
Here we propose to include IT Lib in the C15 program and to 
obtain complementary high resolution spectroscopy in order to 
perform a complete analysis of the physical and chemical 
properties of the stellar components of the binary.  These 
will be compared to models to test whether the timescales of 
the disk ejection model are feasible.

# Targets requested by this program that have been observed (1)
EPIC ID, RA (J2000) [deg], Dec (J2000) [deg], magnitude, Investigation IDs
249249722, 233.328804, -25.026951, 9.495, GO15044_LC|GO15087_LC|GO15038_LC|GO15065_LC