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

作者：Narita Norio^*; Fukui Akihiko; Ikoma Masahiro; Hori Yasunori; Kurosaki Kenji; Kawashima Yui; Nagayama Takahiro; Onitsuka Masahiro; Sukom Amnart; Nakajima Yasushi; Tamura Motohide; Kuroda Daisuke; Yanagisawa Kenshi; Hirano Teruyuki; Kawauchi Kiyoe; Kuzuhara Masayuki; Ohnuki Hiroshi; Suenaga Takuya; Takahashi Yasuhiro H; Izumiura Hideyuki; Kawai Nobuyuki; Yoshida Michitoshi

来源：Astrophysical Journal, 2013, 773(2): 144.

DOI：10.1088/0004-637X/773/2/144

• planetary systems
• planets and satellites: atmospheres
• planets and satellites: individual (GJ1214b)
• stars: individual (GJ1214)
• techniques: photometric

We present five new transit light curves of GJ 1214b taken in the BJHK(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(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-p/R-s = 0.11651 +/- 0.00065 (B band, Subaru/Suprime-Cam), R-p/R-s = 0.11601 +/- 0.00117 (B band, Subaru/FOCAS), R-p/R-s = 0.11654 +/- 0.00080 (J band, IRSF/SIRIUS), R-p/R-s = 0.11550(-0.00153)(+0.00142) (H band, IRSF/SIRIUS), and R-p/R-s = 0.11547 +/- 0.00127 (K-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 %26 Burrows suggest that the high molecular weight atmosphere (e. g., 1% H2O + 99% N-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%26apos;, R-c, and I-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-s = 44.3 +/- 1.2 days and semi-amplitudes of 2.1% +/- 0.4% in the g%26apos; band, 0.56% +/- 0.08% in the R-c band, and 0.32% +/- 0.04% in the Ic band.

• 出版日期2013-8-20
• 单位中国科学院国家天文台