MULTI-COLOR TRANSIT PHOTOMETRY OF GJ 1214b THROUGH BJHK{sub s} BANDS AND A LONG-TERM MONITORING OF THE STELLAR VARIABILITY OF GJ 1214

Journal Article · Tue Aug 20 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/773/2/144· OSTI ID:22130965

Narita, Norio; Hori, Yasunori; Onitsuka, Masahiro; Sukom, Amnart; Tamura, Motohide; Suenaga, Takuya; Takahashi, Yasuhiro H. ^[1]; Fukui, Akihiko; Kuroda, Daisuke; Yanagisawa, Kenshi ^[2]; Ikoma, Masahiro; Kurosaki, Kenji; Kawashima, Yui ^[3]; Nagayama, Takahiro ^[4]; Nakajima, Yasushi ^[5]; Hirano, Teruyuki; Kawauchi, Kiyoe; Kuzuhara, Masayuki; Ohnuki, Hiroshi ^[6]; Izumiura, Hideyuki ^[7] ; others, and

---

1. National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
2. Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232 (Japan)
3. Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-0033 (Japan)
4. Department of Astrophysics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
5. Hitotsubashi University, 2-1 Naka, Kunitachi, Tokyo 186-8601 (Japan)
6. Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)
7. Graduate University for Advanced Studies, Shonan Village, Hayama, Kanagawa 240-0193 (Japan)

We present five new transit light curves of GJ 1214b taken in the BJHK{sub s} bands. Two transits were observed in the B band using the Subaru Prime Focus Camera (Suprime-Cam) and the Faint Object Camera and Spectrograph (FOCAS) instruments on board the Subaru 8.2 m telescope, and one transit was done in the JHK{sub s} bands simultaneously with the Simultaneous Infrared Imager for Unbiased Survey (SIRIUS) camera on the Infrared Survey Facility (IRSF) 1.4 m telescope. Markov Chain Monte Carlo analyses show that the planet-to-star radius ratios are R{sub p}/R{sub s} = 0.11651 {+-} 0.00065 (B band, Subaru/Suprime-Cam), R{sub p}/R{sub s} = 0.11601 {+-} 0.00117 (B band, Subaru/FOCAS), R{sub p}/R{sub s} = 0.11654 {+-} 0.00080 (J band, IRSF/SIRIUS), R{sub p}/R{sub s}= 0.11550{sup +0.00142}{sub -0.00153} (H band, IRSF/SIRIUS), and R{sub p}/R{sub s} = 0.11547 {+-} 0.00127 (K{sub s} band, IRSF/SIRIUS). The Subaru Suprime-Cam transit photometry shows a possible spot-crossing feature. Comparisons of the new transit depths and those from previous studies with the theoretical models by Howe and Burrows suggest that the high molecular weight atmosphere (e.g., 1% H{sub 2}O + 99% N{sub 2}) models are most likely, however, the low molecular weight (hydrogen-dominated) atmospheres with extensive clouds are still not excluded. We also report a long-term monitoring of the stellar brightness variability of GJ 1214 observed with the MITSuME 50 cm telescope in the g', R{sub c}, and I{sub c} bands simultaneously. The monitoring was conducted for 32 nights spanning 78 nights in 2012, and we find a periodic brightness variation with a period of P{sub s} = 44.3 {+-} 1.2 days and semi-amplitudes of 2.1% {+-} 0.4% in the g' band, 0.56% {+-} 0.08% in the R{sub c} band, and 0.32% {+-} 0.04% in the I{sub c} band.

• OSTI ID: 22130965
• Journal Information: Astrophysical Journal, Vol. 773, Issue 2; 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
BRIGHTNESS
CAMERAS
COLOR
HYDROGEN
INFRARED SURVEYS
MARKOV PROCESS
MOLECULAR WEIGHT
MONTE CARLO METHOD
PHOTOMETRY
PLANETS
STARS
TELESCOPES
VISIBLE RADIATION