Detecting and Characterizing Exoplanets: The GJ 436 and HD 149026 Systems

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Detecting and Characterizing Exoplanets: The GJ 436 and HD 149026 Systems

Post by Stalker on 23rd November 2013, 4:41 pm

Waiting for the full paper...
This research utilized the Spitzer Space Telescope to make secondary eclipse measurements, when the exoplanet passes behind its parent star, to provide direct measurements of emitted planetary flux. Multiple observations at different wavelengths help to constrain a planet's thermal profile and atmospheric composition. We will present dayside atmospheric constraints of two known extrasolar planets, GJ 436b and HD 149026b, and discuss the serendipitous discovery of UCF-1.01 and UCF-1.02, two sub-Earth-sized exoplanet candidates. The Neptune-sized exoplanet GJ 436b transits a relatively cool M-dwarf star in a 2.64-day orbit. With an equilibrium temperature of only 714 K, the dominant carbon-bearing species in GJ 436b's atmosphere is expected to be methane, not carbon monoxide. However, Spitzer observations of the system during secondary eclipse indicate a possible methane deficiency by a factor of ~7000. We will present additional atmospheric constraints and discuss several disequilibrium processes as possible explanations. The Saturn-sized exoplanet HD 149026b transits a large, relatively hot parent star at a distance of only 0.042 AU. The planet's high average density suggests that most of HD 149026b's mass must be in its large, icy/rocky core. Previous work reported contradicting eclipse depths at 8.0 microns. We reanalyzed these data and combined the results with nine new secondary-eclipse observations at five infrared wavelengths to present constraints on the thermal profile and atmospheric composition of HD 149026b. UCF-1.01 and UCF-1.02 are extrasolar planet candidates only two-thirds the size of the Earth. These objects transit the nearby M-dwarf star GJ 436 (located only 33 ly away). We will describe two new techniques that played a critical role in their detection, present details on eliminating false positives, and hypothesize possible atmospheric end states. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA, which provided support for this work.
http://adsabs.harvard.edu/abs/2013AAS...22131505S

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Re: Detecting and Characterizing Exoplanets: The GJ 436 and HD 149026 Systems

Post by Sirius_Alpha on 24th November 2013, 5:19 am

These new planets were mentioned last year.
http://solar-flux.forumandco.com/t1110-new-planets-around-gj-436

I wonder if they are confirmed now.

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Re: Detecting and Characterizing Exoplanets: The GJ 436 and HD 149026 Systems

Post by Stalker on 24th November 2013, 6:06 am

Yeah I know, but it seems that now theire must be "validated". I was waiting for it!

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Re: Detecting and Characterizing Exoplanets: The GJ 436 and HD 149026 Systems

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