* Astronomy

Title: Detection of Thermal Emission from a Super-Earth
Authors: Brice-Olivier Demory (MIT), Michael Gillon (University of Liege), Sara Seager (MIT), Bjoern Benneke (MIT), Drake Deming (University of Maryland), Brian Jackson (Carnegie)

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 microns. Our data analysis consists of a two-part process. In a first step, we perform individual analyses of each dataset and compare several baseline models to optimally account for the systematics affecting each lightcurve. We apply independent photometric correction techniques, including polynomial detrending and pixel-mapping, that yield consistent results at the 1-sigma level. In a second step, we perform a global MCMC analysis including all four datasets, that yields an occultation depth of 131±28ppm, translating to a brightness temperature of 2360±300 K in the IRAC-4.5 micron channel. This occultation depth suggests a low Bond albedo coupled to an inefficient heat transport from the planetary dayside to the nightside, or else possibly that the 4.5-micron observations probe atmospheric layers that are hotter than the maximum equilibrium temperature (i.e., a thermal inversion layer or a deep hot layer). The measured occultation phase and duration are consistent with a circular orbit and improves the 3-sigma upper limit on 55 Cnc e's orbital eccentricity from 0.25 to 0.06.

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First light from a super-Earth spotted

Scientists on a planetary-heat-seeking mission have detected the first infrared light from a super-Earth - in this case, a planet some 40 light-years away. And according to their calculations, 55 Cancri e, a planet just over twice the size of Earth, is throwing off some serious heat.
At a toasty 3,700 degrees Fahrenheit, the planet is hot enough to liquefy steel. And there's not much relief from the scorching heat: Researchers at MIT and other institutions say the planet may lack reflective surfaces such as ice caps, instead absorbing most of the heat from its parent star - much as Earth's dark oceans trap heat from the sun.
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Forty light years from Earth, a rocky world named "55 Cancri e" circles perilously close to a stellar inferno.  Completing one orbit in only 18 hours, the alien planet is 26 times closer to its parent star than Mercury is to the Sun. If Earth were in the same position, the soil beneath our feet would heat up to about 3200 F.  Researchers have long thought that 55 Cancri e must be a wasteland of parched rock.
Now they're thinking again.  New observations by NASA's Spitzer Space Telescope suggest that 55 Cancri e may be wetter and weirder than anyone imagined.
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Title: 55 Cancri: A Coplanar Planetary System that is Likely Misaligned with its Star
Authors: Nathan A. Kaib, Sean N. Raymond, Martin J. Duncan

Although the 55 Cnc system contains multiple, closely packed planets that are presumably in a coplanar configuration, we use numerical simulations to demonstrate that they are likely to be highly inclined to their parent star's spin axis. Due to perturbations from its distant binary companion, this planetary system precesses like a rigid body about its parent star. Consequently, the parent star's spin axis and the planetary orbit normal likely diverged long ago. Because only the projected separation of the binary is known, we study this effect statistically, assuming an isotropic distribution for wide binary orbits. We find that the most likely projected spin-orbit angle is ~50 degrees, with a ~30% chance of a retrograde configuration. Transit observations of the innermost planet - 55 Cnc e - may be used to verify these findings via the Rossiter-McLaughlin effect. 55 Cancri may thus represent a new class of planetary systems with well-ordered, coplanar orbits that are inclined with respect to the stellar equator.

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