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arXiv · 1803.03299

Proper Motion of the Faint Star near KIC 8462852 (Boyajian's Star) - Not a Binary System

Dan P. Clemens·Kush Maheshwari·Rosha Jagani·J. Montgomery·A. M. El Batal·T G. Ellis·J. T. Wright
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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 the two could constitute a binary, which might have implications for the cause of the brightness dips seen by {\it Kepler} (Boyajian et al. (2016) and in ground-based optical studies Boyajian et al. (2018). Here, NIR imaging in 2017 using the Mimir instrument resolved the pair and enabled measuring their separation. The faint star had moved $67 \pm 7$ milliarcsec (mas) relative to KIC 8462852 since 2014. The relative proper motion of the faint star is $23.9 \pm 2.6$ mas yr$^{-1}$, for a tangential velocity of $45 \pm 5$ 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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Dan P. Clemens, Kush Maheshwari, Rosha Jagani, J. Montgomery, A. M. El Batal, T G. Ellis, J. T. Wright. 2018-03-08. Proper Motion of the Faint Star near KIC 8462852 (Boyajian's Star) - Not a Binary System. https://doi.org/10.3847/2041-8213/aab492

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