An asymmetric eclipse seen toward the pre-main-sequence binary system V928 Tau
MetadataShow full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
K2 observations of the weak-lined T Tauri binary V928 Tau A and B show the detection of a single, asymmetric eclipse, which may be due to a previously unknown substellar companion eclipsing one component of the binary with an orbital period >66 days. Over an interval of about 9 hr, one component of the binary dims by around 60%, returning to its normal brightness about 5 hr later. From modeling of the eclipse shape, we find evidence that the eclipsing companion may be surrounded by a disk or a vast ring system. The modeled disk has a radius of 0.9923 ± 0.0005 R*, with an inclination of 5678 ± 003, a tilt of 4122 ± 005, an impact parameter of −0.2506 ± 0.0002 R*, and an opacity of 1.00. The occulting disk must also move at a transverse velocity of 6.637 ± 0.002 R* day−1, which, depending on whether it orbits V928 Tau A or B, corresponds to approximately 73.53 or 69.26 km s−1. A search in ground-based archival data reveals additional dimming events, some of which suggest periodicity, but no unambiguous period associated with the eclipse observed by K2. We present a new epoch of astrometry that is used to further refine the orbit of the binary, presenting a new lower bound of 67 yr, and constraints on the possible orbital periods of the eclipsing companion. The binary is also separated by 18'' (~2250 au) from the lower-mass CFHT-BD-Tau 7, which is likely associated with V928 Tau A and B. We also present new high-dispersion optical spectroscopy that we use to characterize the unresolved stellar binary.
van Dam , D M , Kenworthy , M A , David , T J , Mamajek , E E , Hillenbrand , L A , Cody , A M , Howard , A W , Isaacson , H , Ciardi , D R , Rebull , L M , Stauffer , J R , Patel , R , Cameron , A C , Rodriguez , J E , Pojmanski , G , Gonzales , E J , Schlieder , J E , Hambsch , F-J , Dufoer , S , Vanmunster , T , Dubois , F , Vanaverbeke , S , Logie , L , Rau , S & Collaborators , WASP 2020 , ' An asymmetric eclipse seen toward the pre-main-sequence binary system V928 Tau ' , Astronomical Journal , vol. 160 , no. 6 , 285 . https://doi.org/10.3847/1538-3881/abc259
Copyright © 2020 American Astronomical Society. All rights reserved. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.3847/1538-3881/abc259.
DescriptionFunding: J.D.and E.E.M.gratefully acknowledge support from the Jet Propulsion Laboratory Exoplanetary Science Initiative and NASA award 17-K2GO6-0030.
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.