Details

Autor(en) / Beteiligte

• van Dam, Dirk M.
• Kenworthy, Matthew A.
• David, Trevor J.
• Mamajek, Eric E.
• Hillenbrand, Lynne A.
• Cody, Ann Marie
• Howard, Andrew W.
• Isaacson, Howard
• Ciardi, David R.
• Rebull, Luisa M.
• Stauffer, John R.
• Patel, Rahul
• Cameron + WASP Collaborators, Andrew Collier
• Rodriguez, Joseph E.
• Pojma ski, Grzegorz
• Gonzales, Erica J.
• Schlieder, Joshua E.
• Hambsch, Franz-Josef
• Dufoer, Sjoerd
• Vanmunster, Tonny
• Dubois, Franky
• Vanaverbeke, Siegfried
• Logie, Ludwig
• Rau, Steve

Titel

An Asymmetric Eclipse Seen toward the Pre-main-sequence Binary System V928 Tau

Ist Teil von

• The Astronomical journal, 2020-12, Vol.160 (6), p.285

Ort / Verlag

Madison: The American Astronomical Society

Erscheinungsjahr

2020

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• 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 56 78 0 03, a tilt of 41 22 0 05, 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.