[en] Many kinds of electromagnetic waves and particle beams are used as analytical probes for the investigation of uranium-mineralogy and speciation. The representatives of the probes are SEM, TEM, μ-PIRE, XPS and XAFS. Each of these analytical probes has its own advantages and disadvantages. We have performed studies to compare the advantages and disadvantages on the basis of the analysis of the distribution and speciation of U containing rock samples collected at the Koongarra uranium deposit, Australia. The spatial resolutions of the probes are in the order of TEM>SEM, μ-PIXE>XFAS, XPS. The lower detection limits of the probes are in the order of μ-PIXE< TEM, SEM< XFAS, XPS. Oxidation state of U was determined by XFAS and XPS. These results indicate that combination of the above probes can give us sufficient data on U speciation not only in natural rock samples but in solid samples obtained in the laboratory. (authors)

[en] 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^+0.00142_-0.00153 (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 and Burrows suggest that the high molecular weight atmosphere (e.g., 1% H₂O + 99% N₂) 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_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' band, 0.56% ± 0.08% in the R_c band, and 0.32% ± 0.04% in the I_c band

[en] We present optical (g', R_c, and I_c) to near-infrared (J) simultaneous photometric observations for a primary transit of GJ3470b, a Uranus-mass transiting planet around a nearby M dwarf, by using the 50 cm MITSuME telescope and the 188 cm telescope, both at the Okayama Astrophysical Observatory. From these data, we derive the planetary mass, radius, and density as 14.1 ± 1.3 M_⊕, 4.32^+0.21_-0.10 R_⊕, and 0.94 ± 0.12 g cm^–3, respectively, thus confirming the low density that was reported by Demory et al. based on the Spitzer/IRAC 4.5 μm photometry (0.72^+0.13_-0.12 g cm^–3). Although the planetary radius is about 10% smaller than that reported by Demory et al., this difference does not alter their conclusion that the planet possesses a hydrogen-rich envelope whose mass is approximately 10% of the planetary total mass. On the other hand, we find that the planet-to-star radius ratio (R_p /R_s ) in the J band (0.07577^+0.00072_-0.00075) is smaller than that in the I_c (0.0802 ± 0.0013) and 4.5 μm (0.07806^+0.00052_-0.00054) bands by 5.8% ± 2.0% and 2.9% ± 1.1%, respectively. A plausible explanation for the differences is that the planetary atmospheric opacity varies with wavelength due to absorption and/or scattering by atmospheric molecules. Although the significance of the observed R_p /R_s variations is low, if confirmed, this fact would suggest that GJ3470b does not have a thick cloud layer in the atmosphere. This property would offer a wealth of opportunity for future transmission-spectroscopic observations of this planet to search for certain molecular features, such as H₂O, CH₄, and CO, without being prevented by clouds.