THE PTF ORION PROJECT: A POSSIBLE PLANET TRANSITING A T-TAURI STAR

Journal Article · Fri Aug 10 00:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/755/1/42· OSTI ID:22039143

Van Eyken, Julian C; Ciardi, David R; Von Braun, Kaspar; Kane, Stephen R; Plavchan, Peter; Akeson, Rachel L; Beichman, Charles A; Gelino, Dawn M ^[1]; Bender, Chad F; Mahadevan, Suvrath ^[2]; Brown, Timothy M; Fulton, Benjamin J; Shporer, Avi ^[3]; Crepp, Justin R ^[4]; Howard, Andrew W; Marcy, Geoffrey W ^[5]; Howell, Steve B ^[6]; Szkody, Paula ^[7]; Boden, Andrew F ^[8]; others, and

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1. NASA Exoplanet Science Institute, California Institute of Technology, 770 South Wilson Avenue, M/S 100-22, Pasadena, CA 91125 (United States)
2. Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)
3. Las Cumbres Observatory Global Telescope, Goleta, CA 93117 (United States)
4. Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)
5. Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)
6. NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States)
7. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States)
8. Caltech Optical Observatories, California Institute of Technology, Pasadena, CA 91125 (United States)

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 Almost-Equal-To - 0.22 periods. The amplitude (half range) of the RV variations is 2.4 km s{sup -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{sub p}sin i{sub orb} {approx}< 4.8 {+-} 1.2 M{sub Jup}; when combined with the orbital inclination, i{sub 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{sub p} {approx}< 5.5 {+-} 1.4 M{sub 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.

• OSTI ID: 22039143
• Journal Information: Astrophysical Journal, Vol. 755, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCURACY
AMPLITUDES
ASTRONOMY
ASTROPHYSICS
COMPUTERIZED SIMULATION
DETECTION
DIAGRAMS
EVAPORATION
MASS
OPTICS
PLANETS
RADIAL VELOCITY
SATELLITES
STARSPOTS
T TAURI STARS
TRANSIENTS
VISIBLE RADIATION