105 research outputs found

    Spin-Orbit Alignment of the TrES-4 Transiting Planetary System and Possible Additional Radial Velocity Variation

    Get PDF
    We report new radial velocities of the TrES-4 transiting planetary system, including observations of a full transit, with the High Dispersion Spectrograph of the Subaru 8.2m telescope. Modeling of the Rossiter-McLaughlin effect indicates that TrES-4b has closely aligned orbital and stellar spin axes, with λ=6.3∘±4.7∘\lambda = 6.3^{\circ} \pm 4.7^{\circ}. The close spin-orbit alignment angle of TrES-4b seems to argue against a migration history involving planet-planet scattering or Kozai cycles, although there are two nearby faint stars that could be binary companion candidates. Comparison of our out-of-transit data from 4 different runs suggest that the star exhibits radial velocity variability of ∌\sim20 ms^-1 in excess of a single Keplerian orbit. Although the cause of the excess radial velocity variability is unknown, we discuss various possibilities including systematic measurement errors, starspots or other intrinsic motions, and additional companions besides the transiting planet.Comment: 10 pages, 3 figures, 3 tables, PASJ in pres

    Effectiveness of an image generation method that expresses the visual impression of space for two-point perspective landscapes

    Get PDF
    Photographs and CG images are generally rendered using a perspective projection. However, because a perspective projection image does not always represent the visual impression of a real space, we occasionally feel a sense of incompatibility when viewing such images. We believe that clarifying the human visual characteristics will enable the creation of more realistic images. A previous study investigated the human perception of size in a real space and proposed a magnification-rate function that shows the relationship between the subjective visual size of an object to be drawn and the observation distance. Images applying the magnification-rate function provide an impression closer to that in a real space than do perspective projection images. However, these results have only been verified for single-point landscapes. In this study, to investigate the impression of an image, we applied the magnification-rate function to images portraying landscapes with a two-point perspective. The results show that the magnification-transformed images were evaluated as being closer to the impressions in a real space than those of perspective projected images. This is similar to the evaluation of transformed images for one-point perspective landscapes, suggesting that an image transformation using the magnification-rate function is effective for two-point perspective landscapes

    Subaru HDS Transmission Spectroscopy of the Transiting Extrasolar Planet HD 209458b

    Full text link
    We have searched for absorption in several common atomic species due to the atmosphere or exosphere of the transiting extrasolar planet HD 209458b, using high precision optical spectra obtained with the Subaru High Dispersion Spectrograph (HDS). Previously we reported an upper limit on H alpha absorption of 0.1% (3 sigma) within a 5.1\AA band. Using the same procedure, we now report upper limits on absorption due to the optical transitions of Na D, Li, H alpha, H beta, H gamma, Fe, and Ca. The 3 sigma upper limit for each transition is approximately 1% within a 0.3\AA band (the core of the line), and a few tenths of a per cent within a 2\AA band (the full line width). The wide-band results are close to the expected limit due to photon-counting (Poisson) statistics, although in the narrow-band case we have encountered unexplained systematic errors at a few times the Poisson level. These results are consistent with all previously reported detections and upper limits, but are significantly more sensitive.Comment: 10 pages, 9 figure

    Measurement of the Rossiter--McLaughlin Effect in the Transiting Exoplanetary System TrES-1

    Get PDF
    We report a measurement of the Rossiter--McLaughlin effect in the transiting extrasolar planetary system TrES-1, via simultaneous spectroscopic and photometric observations with the Subaru and MAGNUM telescopes. By modeling the radial velocity anomaly that was observed during a transit, we determine the sky-projected angle between the stellar spin axis and the planetary orbital axis to be λ=30±21\lambda = 30 \pm 21 [deg]. This is the third case for which λ\lambda has been measured in a transiting exoplanetary system, and the first demonstration that such measurements are possible for relatively faint host stars (V∌12V \sim 12, as compared to V∌8V \sim 8 for the other systems). We also derive a time of mid-transit, constraints on the eccentricity of the TrES-1b orbit (e=0.048±0.025e = 0.048 \pm 0.025), and upper limits on the mass of the Trojan companions (â‰Č\lesssim14 M⊕M_{\oplus}) at the 3σ\sigma level.Comment: 8 pages, 5 figures, 2 tables. Published in PASJ. Corrected typo

    Further Observations of the Tilted Planet XO-3: A New Determination of Spin-Orbit Misalignment, and Limits on Differential Rotation

    Get PDF
    Abstract: We report on observations of the Rossiter-McLaughlin (RM) effect for the XO-3 exoplanetary system. The RM effect for the system was previously measured by two different groups, but their results were statistically inconsistent. To obtain a decisive result we observed two full transits of XO-3b with the Subaru 8.2-m telescope. By modeling these data with a new and more accurate analytic formula for the RM effect, we find the projected spin-orbit angle to be λ=37.3 deg ± 3.0 deg, in good agreement with the previous finding by Winn et al. (2009). In addition, an offset of ~22 m/s[superscript -1] was observed between the two transit datasets. This offset could be a signal of a third body in the XO-3 system, a possibility that should be checked with future observations. We also attempt to search for a possible signature of the stellar differential rotation in the RM data for the first time, and put weak upper limits on the differential rotation parameters.United States. National Aeronautics and Space Administration (NNX11AG85G

    The Rossiter-McLaughlin Effect of the Transiting Exoplanet XO-4b

    Get PDF
    We report photometric and radial velocity observations of the XO-4 transiting planetary system, conducted with the FLWO 1.2 m telescope and the 8.2 m Subaru Telescope. Based on the new light curves, the refined transit ephemeris of XO-4b is PP == 4.1250828 ± \ \pm\ 0.0000040 d and TcT_{\rm c} [BJDTDB_{\rm TDB}] == 2454485.93323 ± \ \pm\ 0.00039. We measured the Rossiter–McLaughlin effect of XO-4b and estimated the sky-projected angle between the stellar spin axis and the planetary orbital axis to be λ\lambda == −-46∘ ⁣ ⁣ ⁣.^\circ\!\!\!.7   −6∘ ⁣ ⁣ ⁣.1+8∘ ⁣ ⁣ ⁣.1\ ^{{+8^\circ\!\!\!.1}}_{{\ -6^\circ\!\!\!.1}}. This measurement of λ\lambda is less robust than in some other cases because the impact parameter of the transit is small, causing a strong degeneracy between λ\lambda and the projected stellar rotational velocity. Nevertheless, our finding of a spin–orbit misalignment suggests that the migration process for XO-4b involved few-body dynamics rather than interaction with a gaseous disk. In addition, our result conforms with the pattern reported by Winn et al. (2010, ApJ, 718, L145) that high obliquities are preferentially found for stars with effective temperatures hotter than 6250 K.Japan Society for the Promotion of Science (Fellowship for Research DC1: 22-5935)Japan Society for the Promotion of Science (Fellowship for Research PD: 20-8141)United States. National Aeronautics and Space Administration (Origins program grant NNX09AD36G)United States. National Aeronautics and Space Administration (Origins program grant NNX09AB33G

    Improved Measurement of the Rossiter-McLaughlin Effect in the Exoplanetary System HD 17156

    Get PDF
    We present an improved measurement of the Rossiter-McLaughlin effect for the exoplanetary system HD 17156, based on radial-velocity data gathered with the Subaru 8.2m telescope throughout the planetary transit of UT 2008 November 7. The data allow for a precise and independent determination of the projected spin-orbit angle of this system: λ=10.0∘±5.1∘\lambda = 10.0^{\circ} \pm 5.1^{\circ}. This result supersedes the previous claim of λ=62∘±25∘\lambda = 62^{\circ} \pm 25^{\circ} by Narita et al., which was based on lower-precision data with poor statistics. Thus the stellar spin and planetary orbital axes of the HD 17156 system are likely to be well-aligned, despite the planet's large orbital eccentricity suggesting a history of strong dynamical interactions.Comment: 16 pages, 3 figures, 3 tables, PASJ accepte

    Reconsideration of Laparoscopic Cholecystectomy

    Get PDF
    We describe the surgical method of cases showing a distended gallbladder. Because the most important thing does not cause biliary tract injury, it is to find orientation carefully. The frequency of incidental gallbladder cancer was in 7 (0.7%) of the 983. Only cholecystectomy is necessary to be performed for Tis or T1 cancer, and surgery has to be changed to radical surgery for T2 cancer or deeper invasion. Laparoscopic cholecystectomy is already an established standard operation. In the presence of acute or severe chronic inflammation, special attention should be paid to these points
    • 

    corecore