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Identification of partially resolved binaries in Pan-STARRS 1 data

Deacon, N.R.; Magnier, E.A.; Best, W.M.J.; Liu, M.C.; Dupuy, T.J.; Chambers, K.C.; Draper, P.W.; Flewelling, H.; Metcalfe, N.; Tonry, J.L.; Wainscoat, R.J.; Waters, C.

Identification of partially resolved binaries in Pan-STARRS 1 data Thumbnail


N.R. Deacon

E.A. Magnier

W.M.J. Best

M.C. Liu

T.J. Dupuy

K.C. Chambers

P.W. Draper

H. Flewelling

J.L. Tonry

R.J. Wainscoat

C. Waters


Using shape measurement techniques developed for weak lensing surveys, we have identified three new ultracool binaries in the Pan-STARRS 1 (Chambers et al.) survey. Binary companions that are not completely resolved can still alter the shapes of stellar images. These shape distortions can be measured if point spread function anisotropy caused by the telescope is properly accounted for. We show using both a sample of known binary stars and simulated binaries that we can reliably recover binaries wider than around 0.3 arcsec and with flux ratios greater than around 0.1. We then applied our method to a sample of ultracool dwarfs within 30 pc with 293 objects having sufficient Pan-STARRS 1 data for our method. In total, we recovered all but one of the 11 binaries wider than 0.3 arcsec in this sample. Our one failure was a true binary detected with a significant but erroneously high ellipticity that led it to be rejected in our analysis. We identify three new binaries, one a simultaneous discovery, with primary spectral types M6.5, L1 and T0.5. These latter two were confirmed with Keck/Near Infrared Camera 2 follow-up imaging. This technique will be useful for identifying large numbers of stellar and substellar binaries in the upcoming Large Synoptic Survey Telescope and Dark Energy Survey sky surveys.


Deacon, N., Magnier, E., Best, W., Liu, M., Dupuy, T., Chambers, K., …Waters, C. (2017). Identification of partially resolved binaries in Pan-STARRS 1 data. Monthly Notices of the Royal Astronomical Society, 468(3), 3499-3515.

Journal Article Type Article
Acceptance Date Feb 23, 2017
Online Publication Date Feb 17, 2017
Publication Date Jul 1, 2017
Deposit Date Jul 18, 2017
Publicly Available Date Jul 18, 2017
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 468
Issue 3
Pages 3499-3515


Published Journal Article (1.3 Mb)

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2017. The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.

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