1,797 research outputs found

    Physical Properties of the Transiting Planetary System TrES-3

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    We present four new transits of the planetary system TrES-3 observed between 2009 May and 2010 June. Among these, the third transit by itself indicates possible evidence for brightness disturbance, which might be the result of the planet blocking a cool starspot on the stellar surface. A total of 109 transit times, including our measurements, were used to determine the improved ephemeris with a transit epoch of 2454185.910944±\pm0.000072 HJED and an orbital period of 1.30618700±\pm0.00000015 d. We analyzed the transit light curves using the JKTEBOP code and adopting the quadratic limb-darkening law. In order to derive the physical properties of the TrES-3 system, the transit parameters are combined with the empirical relations from eclipsing binary stars and stellar evolutionary models. The stellar mass and radius obtained from a calibration using TAT_A, log ρA\rho_{\rm A} and [Fe/H] are consistent with those from the isochrone analysis. We found that the exoplanet TrES-3b has a mass of 1.93±\pm0.07 MJup_{\rm Jup}, a radius of 1.30±\pm0.04 RJup_{\rm Jup}, a surface gravity of log gbg_{\rm b}=3.45±\pm0.02, a density of 0.82±\pm0.06 ρJup\rho_{\rm Jup}, and an equilibrium temperature of 1641±\pm23 K. The results are in good agreement with theoretical models for gas giant planets.Comment: 15 pages, including 4 figures and 4 tables, accepted for publication in PAS

    Business Groups and Tunneling: Evidence from Private Securities Offerings by Korean Chaebols

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    Using a comprehensive sample of equity-linked private securities offerings by Korean firms from 1989 to 2000, we examine whether such offerings can be used as a mechanism for wealth transfer between issuers and acquirers. For deals involving issuers and acquirers in the same business group (chaebol), the announcement returns for chaebol-affiliated issuers with good past performance are lower than those for other types of issuers if the price discount is larger. In contrast, this deal leads to more value creation for chaebol-affiliated acquirers than other types of acquirers. Furthermore, well-performing chaebol-affiliated acquirers experience a larger wealth loss than other types of acquirers if they buy securities from poorly performing issuers in the same chaebol. We also find that chaebol firms with good past performance tend to sell private securities at a low price to their member firms. This evidence is consistent with tunneling within business groups.
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