THE OPTICAL AND NEAR-INFRARED TRANSMISSION SPECTRUM OF THE SUPER-EARTH GJ 1214b: FURTHER EVIDENCE FOR A METAL-RICH ATMOSPHERE

• Published in: The Astrophysical journal Vol. 743; no. 1; pp. 92 - jQuery1323901027630='48'
• Main Authors: BEAN, Jacob L, DESERT, Jean-Michel, KABATH, Petr, STALDER, Brian, SEAGER, Sara, MILLER-RICCI KEMPTON, Eliza, BERTA, Zachory K, HOMEIER, Derek, WALSH, Shane, SEIFAHRT, Andreas
• Format: Journal Article
• Language: English
• Published: Bristol IOP 10.12.2011
• Subjects: ALGORITHMS; Astronomy; ASTROPHYSICS; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Earth, ocean, space; Exact sciences and technology; PHOTOMETRY; PLANETS; SATELLITE ATMOSPHERES; SATELLITES; SPECTRA; SPECTROSCOPY; WAVELENGTHS; Satellite atmospheres; Spectroscopy; planets and satellites: atmospheres; Algorithms; Planets; Near infrared spectrum; techniques: photometric; Haze; Photometry; Data reduction; planets and satellites: individual (GJ 1214b)
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637x/743/1/92

We present an investigation of the transmission spectrum of the 6.5 M {circled plus} planet GJ 1214b based on new ground-based observations of transits of the planet in the optical and near-infrared, and on previously published data. Observations with the VLT + FORS and Magellan + MMIRS using the technique of multi-object spectroscopy with wide slits yielded new measurements of the planet's transmission spectrum from 0.61 to 0.85 Delta *mm, and in the J, H, and K atmospheric windows. We also present a new measurement based on narrow-band photometry centered at 2.09 Delta *mm with the VLT + HAWKI. We combined these data with results from a reanalysis of previously published FORS data from 0.78 to 1.00 Delta *mm using an improved data reduction algorithm, and previously reported values based on Spitzer data at 3.6 and 4.5 Delta *mm. All of the data are consistent with a featureless transmission spectrum for the planet. Our K-band data are inconsistent with the detection of spectral features at these wavelengths reported by Croll and collaborators at the level of 4.1 Delta *s. The planet's atmosphere must either have at least 70% H2O by mass or optically thick high-altitude clouds or haze to be consistent with the data.