Examinando por Autor "Bailey, J."

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    GJ 832c: a super-earth in the habitable zone
    (Institute of Physics Publishing, 2014-08) Wittenmyer, Robert A.; Tuomi, Mikko; Butler, R.P.; Jones, H.R.A.; Anglada-Escudé, Guillem; Horner, Jonathan; Tinney, C.G; Marshall, J.P.; Carter, B.D.; Bailey, J.; Salter, G.S.; O'Toole, S.J.; Wright, D.; Crane, J.D.; Schectman, S.A.; Arriagada, P.; Thompson, I.; Minniti, D.; Jenkins, J.S.; Diaz, M.
    We report the detection of GJ 832c, a super-Earth orbiting near the inner edge of the habitable zone of GJ 832, an M dwarf previously known to host a Jupiter analog in a nearly circular 9.4 yr orbit. The combination of precise radial velocity measurements from three telescopes reveals the presence of a planet with a period of 35.68 ± 0.03 days and minimum mass (m sin i) of 5.4 ± 1.0 Earth masses. GJ 832c moves on a low-eccentricity orbit (e = 0.18±0.13) toward the inner edge of the habitable zone. However, given the large mass of the planet, it seems likely that it would possess a massive atmosphere, which may well render the planet inhospitable. Indeed, it is perhaps more likely that GJ 832c is a “super-Venus,” featuring significant greenhouse forcing. With an outer giant planet and an interior, potentially rocky planet, the GJ 832 planetary system can be thought of as a miniature version of our own solar system.
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    MagAO IMAGING OF LONG-PERIOD OBJECTS (MILO). II. A PUZZLING WHITE DWARF AROUND THE SUN-LIKE STAR HD 11112
    (IOP PUBLISHING, 2016-11) Rodigas, T.J.; Bergeron, P.; Simon, A.; Arriagada, P.; Faherty, J.K.; Anglada-Escudé, G.; Mamajek, E.E.; Weinberger, A.; Butler, R.P.; Males, J.R.; Morzinski, K.; Close, L.M.; Hinz, P.M.; Bailey, J.; Carter, B.; Jenkins, J.S.; Jones, H.; O'Toole, S.; Tinney, C.G.; Wittenmyer, R.; Debes, J.
    HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan Adaptive Optics system. We detect the object (HD 11112B) at a separation of 2 2 (100 au) at multiple wavelengths spanning 0.6-4 mu m. and show that it is most likely a gravitationally bound cool white dwarf. Modeling its spectral energy distribution suggests that its mass is 0.9-1.1M(circle dot), which corresponds to very high eccentricity, near edge-on orbits from a. Markov chain Monte Carlo analysis of the RV and imaging data together. The total age of the white dwarf is > 2 sigma, which is discrepant with that of the primary star under most assumptions. The problem can be resolved if the white dwarf progenitor was initially a double white dwarf binary that then merged into the observed high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object that can be used to calibrate atmospheric and evolutionary models of cool white dwarfs and should thus continue to be monitored by RV and direct imaging over the coming years.