Violent variation of transit depths and an ingress-egress asymmetry of the transit light curve discovered in KIC 12557548 have been interpreted as evidences of a catastrophic evaporation of atmosphere with dust (Ṁ p 1M ⊕ Gyr −1 ) from a close-in small planet. To explore what drives the anomalous atmospheric escape, we perform time-series analysis of the transit depth variation of Kepler archival data for ∼ 3.5 yr. We find a ∼ 30% periodic variation of the transit depth with P 1 = 22.83 ± 0.21 days, which is within the error of the rotation period of the host star estimated using the light curve modulation, P rot = 22.91 ± 0.24 days. We interpret the results as evidence that the atmospheric escape of KIC 12557548b correlates with stellar activity. We consider possible scenarios that account for both the mass loss rate and the correlation with stellar activity. X-ray and ultraviolet (XUV)-driven evaporation is possible if one accepts a relatively high XUV flux and a high efficiency for converting the input energy to the kinetic energy of the atmosphere. Star-planet magnetic interaction is another possible scenario though huge uncertainty remains for the mass loss rate.
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 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 H 2 O, CH 4 , and CO, without being prevented by clouds. Subject headings: planetary systems -planets and satellites: atmosphere -planets and satellites:individual(GJ3470b) -stars: individual(GJ3470) -techniques: photometric
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 = 0.11654±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 & Burrows (2012) 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
We examined the usefulness of thiosulfate as an indicator of hydrogen sulfide poisoning by analysing sulfide and thiosulfate in three cases. In the first (non-fatal) case sulfide and thiosulfate were not detected in the blood samples from any of the four workers involved in the accident. In the urine samples, only thiosulfate was detected in three out of the four workers at a concentration of 0.12-0.43 micromol/ml, which was 4-14 times higher than the level in a healthy person. In the second (fatal) case sulfide and thiosulfate were detected in the blood sample at concentrations of 0.007 micromol/ml for sulfide, and 0.025 micromol/ml for thiosulfate. The thiosulfate concentration was at least 8 times higher than the level in a healthy person. In the third (fatal) case sulfide and thiosulfate were detected in the blood sample at concentrations of 0.95 micromol/ml for sulfide, and 0.12 micromol/ml for thiosulfate. Based on the above results, we concluded that thiosulfate in urine is the only indicator to prove hydrogen sulfide poisoning in non-fatal cases, while the analysis of sulfide in fatal cases should be accompanied by the measurement of thiosulfate in blood.
An acyl-CoA hydrolase, referred to as hBACH, was purified from human brain cytosol. The enzyme had a molecular mass of 100 kDa and 43-kDa subunits, and was highly active with long-chain acyl-CoAs, e.g. a maximal velocity of 295 micromol/min/mg and K(m) of 6.4 microM for palmitoyl-CoA. Acyl-CoAs with carbon chain lengths of C(8-18) were also good substrates. In human brain cytosol, 85% of palmitoyl-CoA hydrolase activity was titrated by an anti-BACH antibody, which accounted for over 75% of the enzyme activity found in the brain tissue. The cDNA isolated for hBACH, when expressed in Escherichia coli, directed the expression of palmitoyl-CoA hydrolase activity and a 44-kDa protein immunoreactive to the anti-BACH antibody, which in turn neutralized the hydrolase activity. The hBACH cDNA encoded a 338-amino acid sequence which was 95% identical to that of a rat homolog. The hBACH gene spanned about 130 kb and comprised 9 exons, and was mapped to 1p36.2 on the cytogenetic ideogram. These findings indicate that the long-chain acyl-CoA hydrolase present in the brain is well conserved between man and the rat, suggesting a conserved role for this enzyme in the mammalian brain, and enabling genetic studies on the functional analysis of acyl-CoA hydrolase.
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