Proper motion of the faint star near KIC 8462852 (Boyajian's Star)-not a binary system

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Date
2018-03-20
Authors
Clemens, Dan P.
Maheshwari, Kush
Jagani, Roshan
Montgomery, J.
El Batal, A.M.
Ellis, T.G.
Wright, J.T.
Version
OA Version
Citation
Dan P Clemens, Kush Maheshwari, Roshan Jagani, J Montgomery, AM El Batal, TG Ellis, JT Wright. 2018. "Proper Motion of the Faint Star near KIC 8462852 (Boyajian's Star)-Not a Binary System." The Astrophysical Journal Letters, Volume 856, Number 1
Abstract
A faint star located 2 arcsec from KIC 8462852 was discovered in Keck 10 m adaptive optics imaging in the JHK near-infrared (NIR) in 2014 by Boyajian et al. (2016). The closeness of the star to KIC 8462852 suggested that the two could constitute a binary, which might have implications for the cause of the brightness dips seen by Kepler and in ground-based optical studies. Here, NIR imaging in 2017 using the Mimir instrument resolved the pair and enabled measuring their separation. The faint star had moved 67 ± 7 milliarcsec (mas) relative to KIC 8462852 since 2014. The relative proper motion of the faint star is 23.9 ± 2.6 mas yr−1, for a tangential velocity of 45 ± 5 km s−1 if it is at the same 390 pc distance as KIC 8462852. Circular velocity at the 750 au current projected separation is 1.5 km s−1, hence the star pair cannot be bound.
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The published version of this article is © 2018. The American Astronomical Society. All rights reserved.