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Astrophysicists Prepare Weather Forecasts for Planets Beyond our Solar System

posted by takyon on Thursday May 14 2015, @09:26AM   
from the do-I-need-an-umbrella dept.

AnonTechie writes:

From the University of Toronto:

"Cloudy for the morning, turning to clear with scorching heat in the afternoon." While this might describe a typical late-summer day in many places on Earth, it may also apply to planets outside our solar system, according to a new study by an international team of astrophysicists from the University of Toronto, York University and Queen's University Belfast.

Using sensitive observations from the Kepler space telescope, the researchers have uncovered evidence of daily weather cycles on six extra-solar planets seen to exhibit different phases. Such phase variations occur as different portions of these planets reflect light from their stars, similar to the way our own moon cycles though different phases.

Among the findings are indications of cloudy mornings on four of them and hot, clear afternoons on two others. "We determined the weather on these alien worlds by measuring changes as the planets circle their host stars, and identifying the day-night cycle," said Lisa Esteves, a PhD candidate in the Department of Astronomy & Astrophysics at the University of Toronto, and lead author of the study published today in The Astrophysical Journal.

"We traced each of them going through a cycle of phases in which different portions of the planet are illuminated by its star, from fully lit to completely dark," said Esteves.

[Paper]: http://arxiv.org/abs/1407.2245

• Here is the paper abstract (Score: 3, Insightful) by hubie on Thursday May 14 2015, @04:29PM

  by hubie (1068) on Thursday May 14 2015, @04:29PM (#182974) Journal

  We present a comprehensive analysis of planetary phase variations, including possible planetary light offsets, using eighteen quarters of data from the Kepler space telescope. After correcting for systematics, we found fourteen systems with significant detections in each of the phase curve components: planet's phase function, secondary eclipse, Doppler boosting and ellipsoidal variations. We model the full phase curve simultaneously, including primary and secondary transits, and derive albedos, day- and night-side temperatures and planet masses. Most planets manifest low optical geometric albedos (<0.25), with the exception of Kepler-10b, Kepler-91b and KOI-13b. We find that KOI-13b, with a small eccentricity of 0.0006+\-0.0001, is the only planet for which an eccentric orbit is favored. We detect a third harmonic with an amplitude of 1.9+\-0.2 ppm for HAT-P-7b for the first time, and confirm the third harmonic for KOI-13b reported in Esteves et al. : both could be due to their spin-orbit misalignments. For six planets, we report a planetary brightness peak offset from the substellar point: of those, the hottest two (Kepler-76b and HAT-P-7b) exhibit pre-eclipse shifts or to the evening-side, while the cooler four (Kepler-7b, Kepler-8b, Kepler-12b and Kepler-41b) peak post-eclipse or on the morning-side. Our findings dramatically increase the number of Kepler planets with detected planetary light offsets, and provide the first evidence in the Kepler data for a correlation between the peak offset direction and the planet's temperature. Such a correlation could arise if thermal emission dominates light from hotter planets that harbor hot spots shifted toward the evening-side, as theoretically predicted, while reflected light dominates cooler planets with clouds on the planet's morning-side.

  It looks like high precision photometric investigation of these planets. All appropriate and good fodder for astronomers and astrophysicists. I don't understand the gripes about relevance and general hate directed at this.

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