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Measurement Of Spin-Orbit Misalignment And Nodal Precession For The Planet Around Pre-Main-Sequence Star Ptfo 8-8695 From Gravity Darkening, Jason W. Barnes, Julian C. Van Eyken, Brian K. Jackson, David R. Ciardi, Jonathan J. Fortney
Measurement Of Spin-Orbit Misalignment And Nodal Precession For The Planet Around Pre-Main-Sequence Star Ptfo 8-8695 From Gravity Darkening, Jason W. Barnes, Julian C. Van Eyken, Brian K. Jackson, David R. Ciardi, Jonathan J. Fortney
Brian Jackson
PTFO 8-8695b represents the first transiting exoplanet candidate orbiting a pre-main-sequence star (van Eyken et al. 2012, ApJ, 755, 42). We find that the unusual lightcurve shapes of PTFO 8-8695 can be explained by transits of a planet across an oblate, gravity-darkened stellar disk. We develop a theoretical framework for understanding precession of a planetary orbit’s ascending node for the case when the stellar rotational angular momentum and the planetary orbital angular momentum are comparable in magnitude. We then implement those ideas to simultaneously and self-consistently fit two separate lightcurves observed in 2009 December and 2010 December. Our two self-consistent …
Detection Of Thermal Emission From A Super-Earth, Brice-Olivier Demory, Michaël Gillon, Sara Seager, Bjoern Benneke, Drake Deming, Brian Jackson
Detection Of Thermal Emission From A Super-Earth, Brice-Olivier Demory, Michaël Gillon, Sara Seager, Bjoern Benneke, Drake Deming, Brian Jackson
Brian Jackson
We report on the detection of infrared light from the super-Earth 55 Cnc e, based on four occultations obtained with Warm Spitzer at 4.5 μm. Our data analysis consists of a two-part process. In a first step, we perform individual analyses of each data set and compare several baseline models to optimally account for the systematics affecting each light curve. We apply independent photometric correction techniques, including polynomial detrending and pixel mapping, that yield consistent results at the 1σ level. In a second step, we perform a global Markov Chain Monte Carlo analysis, including all four data sets that yield …
Kepler And Ground-Based Transits Of The Exo-Neptune Hat-P-11b, Drake Deming, Pedro V. Sada, Brian Jackson, Steven W. Peterson, Eric Agol, Heather A. Knutson, Donald E. Jennings, Flynn Haase, Kevin Bays
Kepler And Ground-Based Transits Of The Exo-Neptune Hat-P-11b, Drake Deming, Pedro V. Sada, Brian Jackson, Steven W. Peterson, Eric Agol, Heather A. Knutson, Donald E. Jennings, Flynn Haase, Kevin Bays
Brian Jackson
We analyze 26 archival Kepler transits of the exo-Neptune HAT-P-11b, supplemented by ground-based transits observed in the blue (B band) and near-IR (J band). Both the planet and host star are smaller than previously believed; our analysis yields Rp = 4.31 R⊕ ± 0.06 R ⊕ and Rs = 0.683 R☉ ± 0.009 R☉, both about 3σ smaller than the discovery values. Our ground-based transit data at wavelengths bracketing the Kepler bandpass serve to check the wavelength dependence of stellar limb darkening, and the J-band transit provides a precise and independent constraint on the transit duration. Both the limb darkening …
Too Little, Too Late: How The Tidal Evolution Of Hot Jupiters Affects Transit Surveys Of Clusters, John H. Debes, Brian Jackson
Too Little, Too Late: How The Tidal Evolution Of Hot Jupiters Affects Transit Surveys Of Clusters, John H. Debes, Brian Jackson
Brian Jackson
The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense Hubble Space Telescope search for transits. We find that in older clusters, one expects to detect fewer transiting planets by a factor of 2 for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up …
Tidal Limits To Planetary Habitability, Rory Barnes, Brian Jackson, Richard Greenberg, Sean N. Raymond
Tidal Limits To Planetary Habitability, Rory Barnes, Brian Jackson, Richard Greenberg, Sean N. Raymond
Brian Jackson
The habitable zones (HZs) of main-sequence stars have traditionally been defined as the range of orbits that intercept the appropriate amount of stellar flux to permit surface water on a planet. Terrestrial exoplanets discovered to orbit M stars in these zones, which are close-in due to decreased stellar luminosity, may also undergo significant tidal heating. Tidal heating may span a wide range for terrestrial exoplanets and may significantly affect conditions near the surface. For example, if heating rates on an exoplanet are near or greater than that on Io (where tides drive volcanism that resurfaces the planet at least every …
The Hd 40307 Planetary System: Super-Earths Or Mini-Neptunes?, Rory Barnes, Brian Jackson, Sean N. Raymond, Andrew A. West, Richard Greenberg
The Hd 40307 Planetary System: Super-Earths Or Mini-Neptunes?, Rory Barnes, Brian Jackson, Sean N. Raymond, Andrew A. West, Richard Greenberg
Brian Jackson
Three planets with minimum masses less than 10 M⊕ orbit the star HD 40307, suggesting these planets may be rocky. However, with only radial velocity data, it is impossible to determine if these planets are rocky or gaseous. Here we exploit various dynamical features of the system in order to assess the physical properties of the planets. Observations allow for circular orbits, but a numerical integration shows that the eccentricities must be at least 10–4. Also, planets b and c are so close to the star that tidal effects are significant. If planet b has tidal parameters similar to the …
Tidal Heating Of Terrestrial Extrasolar Planets And Implications For Their Habitability, Brian Jackson, Rory Barnes, Richard Greenberg
Tidal Heating Of Terrestrial Extrasolar Planets And Implications For Their Habitability, Brian Jackson, Rory Barnes, Richard Greenberg
Brian Jackson
The tidal heating of hypothetical rocky (or terrestrial) extrasolar planets spans a wide range of values depending on stellar masses and initial orbits. Tidal heating may be sufficiently large (in many cases, in excess of radiogenic heating) and long-lived to drive plate tectonics, similar to the Earth's, which may enhance the planet's habitability. In other cases, excessive tidal heating may result in Io-like planets with violent volcanism, probably rendering them unsuitable for life. On water-rich planets, tidal heating may generate subsurface oceans analogous to Europa's with similar prospects for habitability. Tidal heating may enhance the outgassing of volatiles, contributing to …