THE PTF orion project: a possible planet transiting a T-Tauri star

van Eyken, Julian C. and Ciardi, David R. and von Braun, Kaspar and Kane, Stephen R. and Plavchan, Peter and Bender, Chad F. and Brown, Timothy M. and Crepp, Justin R. and Fulton, Benjamin J. and Howard, Andrew W. and Howell, Steve B. and Mahadevan, Suvrath and Marcy, Geoffrey W. and Shporer, Avi and Szkody, Paula and Akeson, Rachel L. and Beichman, Charles A. and Boden, Andrew F. and Gelino, Dawn M. and Hoard, D. W. and Ramirez, Solange V. and Rebull, Luisa M. and Stauffer, John R. and Bloom, Joshua S. and Cenko, S. Bradley and Kasliwal, Mansi M. and Kulkarni, Shrinivas R. and Law, Nicholas M. and Nugent, Peter E. and Ofek, Eran O. and Poznanski, Dovi and Quimby, Robert M. and Walters, Richard and Grillmair, Carl J. and Laher, Russ and Levitan, David B. and Sesar, Branimir and Surace, Jason A. (2012) THE PTF orion project: a possible planet transiting a T-Tauri star. The Astrophysical Journal, 755 (1). pp. 42-55. ISSN 0004-637X

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We report observations of a possible young transiting planet orbiting a previously known weak-lined T-Tauri star in the 7-10 Myr old Orion-OB1a/25-Ori region. The candidate was found as part of the Palomar Transient Factory (PTF) Orion project. It has a photometric transit period of 0.448413 ± 0.000040 days, and appears in both 2009 and 2010 PTF data. Follow-up low-precision radial velocity (RV) observations and adaptive optics imaging suggest that the star is not an eclipsing binary, and that it is unlikely that a background source is blended with the target and mimicking the observed transit. RV observations with the Hobby-Eberly and Keck telescopes yield an RV that has the same period as the photometric event, but is offset in phase from the transit center by - 0.22 periods. The amplitude (half range) of the RV variations is 2.4 km s-1 and is comparable with the expected RV amplitude that stellar spots could induce. The RV curve is likely dominated by stellar spot modulation and provides an upper limit to the projected companion mass of M psin i orb ≲ 4.8 ± 1.2 M Jup; when combined with the orbital inclination, i orb, of the candidate planet from modeling of the transit light curve, we find an upper limit on the mass of the planetary candidate of M p ≲ 5.5 ± 1.4 M Jup. This limit implies that the planet is orbiting close to, if not inside, its Roche limiting orbital radius, so that it may be undergoing active mass loss and evaporation.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Access to published version in accordance with the copyright policy of the publisher.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 07 Jun 2017 22:14
Last Modified: 27 Jun 2017 04:31
Uncontrolled Keywords: CVSO 30; open clusters and associations; 25 Ori; planets and satellite detection; PTFO 8-8695; stars; pre-main sequence
Fields of Research (2008): 02 Physical Sciences > 0201 Astronomical and Space Sciences > 020110 Stellar Astronomy and Planetary Systems
Fields of Research (2020): 51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510109 Stellar astronomy and planetary systems
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences
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