We present 5 new transit light curves of GJ 1214b taken in BJHK _ { s } -bands .
Two transits were observed in B -band using the Suprime-Cam and the FOCAS instruments onboard the Subaru 8.2m telescope , and one transit was done in JHK _ { s } -bands simultaneously with the SIRIUS camera on the IRSF 1.4m telescope .
MCMC analyses show that the planet-to-star radius ratios are , R _ { p } / R _ { s } = 0.11651 \pm 0.00065 ( B -band , Subaru/Suprime-Cam ) , R _ { p } / R _ { s } = 0.11601 \pm 0.00117 ( B -band , Subaru/FOCAS ) , R _ { p } / R _ { s } = 0.11654 \pm 0.00080 ( J -band , IRSF/SIRIUS ) , R _ { p } / R _ { s } = 0.11550 ^ { +0.00142 } _ { -0.00153 } ( H -band , IRSF/SIRIUS ) , and R _ { p } / R _ { s } = 0.11547 \pm 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 & Burrows ( 21 ) suggest that the high molecular weight atmosphere ( e.g. , 1 % H _ { 2 } O + 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 50cm telescope in g ^ { \prime } - , R _ { \mathrm { c } } - , and I _ { \mathrm { 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 \pm 1.2 days and semi-amplitudes of 2.1 % \pm 0.4 % in g ^ { \prime } -band , 0.56 % \pm 0.08 % in R _ { \mathrm { c } } -band , and 0.32 % \pm 0.04 % in I _ { \mathrm { c } } -band .