THE NATURE OF THE ATMOSPHERE OF THE TRANSITING SUPER-EARTH GJ 1214b

Journal Article · Thu Jun 10 04:00:00 EDT 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/716/1/L74· OSTI ID:21451093

Miller-Ricci, Eliza

The newly discovered planet GJ 1214b is the first known transiting super-Earth requiring a significant atmosphere to explain its observed mass and radius. Models for the structure of this planet predict that it likely possesses an H-He envelope of at least 0.05% of the total mass of the planet. However, models without a significant H-He atmosphere are not entirely ruled out by the available data. Here, we explore a range of possible atmospheres for the planet, ranging from solar composition gas, to pure CO{sub 2} or water (steam). We present transmission and emission spectra for each of these cases. We find that, if GJ 1214b possesses a hydrogen-rich atmosphere as expected, then the primary transit depth for such an atmosphere would vary at a level of up to 0.3% as a function of wavelength, relative to the background light of its M-dwarf host star. Observations at this level of precision are potentially obtainable with current space-based instrumentation. Successful detection of the transmission signature of this planet at the {approx}0.1% level would therefore provide confirmation of the hydrogen-rich nature of the planetary atmosphere. It follows that transmission spectroscopy at this level of precision could provide a first glimpse into answering the question of whether planets in the super-Earth mass regime (1-10 M{sub +}) more closely resemble large terrestrial planets or small gas giant planets.

• OSTI ID: 21451093
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 716; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ATMOSPHERES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
EMISSION SPECTRA
OXIDES
OXYGEN COMPOUNDS
PLANETARY ATMOSPHERES
PLANETS
SPECTRA
SPECTROSCOPY
STARS
WAVELENGTHS