Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b

By Laura Kreidberg, J. Bean, J. D'esert, Björn Benneke, D. Deming, Kevin B. Stevenson, Sara Seager, Z. Berta-Thompson, A. Seifahrt, Derek Homeier. 2013

755 citations recorded by the source corpus.

Recent surveys have revealed that planets intermediate in size between Earth and Neptune (‘super-Earths’) are among the most common planets in the Galaxy. Atmospheric studies are the next step towards developing a comprehensive understanding of this new class of object. Much effort has been focused on using transmission spectroscopy to characterize the atmosphere of the super-Earth archetype GJ 1214b (refs 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17), but previous observations did not have sufficient precision to distinguish between two interpretations for the atmosphere. The planet’s atmosphere could be dominated by relatively heavy molecules, such as water (for example, a 100 per cent water vapour composition), or it could contain high-altitude clouds that obscure its lower layers. Here we report a measurement of the transmission spectrum of GJ 1214b at near-infrared wavelengths that definitively resolves this ambiguity. The data, obtained with the Hubble Space Telescope, are sufficiently precise to detect absorption features from a high mean-molecular-mass atmosphere. The observed spectrum, however, is featureless. We rule out cloud-free atmospheric models with compositions dominated by water, methane, carbon monoxide, nitrogen or carbon dioxide at greater than 5σ confidence. The planet’s atmosphere must contain clouds to be consistent with the data.

Subfields: Astronomy and Astrophysics, Instrumentation

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. N. Madhusudhan
2. Jon Fortney
3. D. Charbonneau
4. A. Showman
5. Sara Seager
6. D. Deming
7. D. Sing
8. H. Knutson

In Instrumentation

1. N. Madhusudhan
2. Jon Fortney
3. D. Charbonneau
4. A. Showman
5. J. Southworth
6. M. Line
7. Sara Seager
8. D. Sing

Citations in the corpus

• PLANETARY CANDIDATES FROM THE FIRST YEAR OF THE K2 MISSION (2015, background): “…transiting planets are important for learning about the masses and compositions of small exoplanets through radial velocity measurements (Marcy et al. 2014; Dressing et al. 2015), and for learning about planetary atmospheres through transit spectroscopy (Knutson et al. 2014; Kreidberg et al. 2014).”
• The Transit Light Source Effect: False Spectral Features and Incorrect Densities for M-dwarf Transiting Planets (2017, background): “…in existing HST/WFC3 transit observations of TRAPPIST1b and TRAPPIST-1c covering 1.1–1.7 µm with the G141 grism (de Wit et al. 2016), though the precision of G141 observations has allowed for the detection of large spot crossing events in other M dwarf transit observations (Kreidberg et al. 2014).”
• A PRECISE WATER ABUNDANCE MEASUREMENT FOR THE HOT JUPITER WASP-43b (2014, methodology): “We extracted spectroscopic light curves from the data using a technique outlined in past work (Kreidberg et al. 2014).”
• CHARACTERIZING K2 PLANET DISCOVERIES: A SUPER-EARTH TRANSITING THE BRIGHT K DWARF HIP 116454 (2014, background): “…exoplanets around bright, nearby stars is important because measuring the precise masses and radii of transiting planets allows for characterization of their interior structures and atmospheres (Charbonneau et al. 2002; Rogers 2014; Knutson et al. 2014; Teske et al. 2013; Kreidberg et al. 2014).”
• Spectrally resolved detection of sodium in the atmosphere of HD 189733b with the HARPS spectrograph (2015, background): “…these encouraging works, the presence of scattering hazes and clouds (Lecavelier Des Etangs et al. 2008a,b; Pont et al. 2013) in several exoplanets prevented the detection of major chemical constituents at low to medium resolution even from space (e.g., Kreidberg et al. 2014; Sing et al. 2015).”
• DETECTION OF AN ATMOSPHERE AROUND THE SUPER-EARTH 55 CANCRI E (2015, methodology): “We correct these systematics using an approach similar to Kreidberg et al. (2014b).”
• THE MUSCLES TREASURY SURVEY. I. MOTIVATION AND OVERVIEW (2016, background): “GJ 1214b is a transiting super-Earth (Mplan ≈ 6.5 M⊕, aplan = 0.014 AU; Charbonneau et al. 2009), possibly harboring a dense, water-rich (Bean et al. 2010; Désert et al. 2011) and likely cloudy (Kreidberg et al. 2014) atmosphere.”
• HST hot-Jupiter transmission spectral survey: detection of potassium in WASP-31b along with a cloud deck and Rayleigh scattering (2014, methodology): “3.0.2 WFC3 white-light curve fits WFC3 is now being used extensively for transiting exoplanet work (Berta et al. 2012; Gibson et al. 2012; Deming et al. 2013; Huitson et al. 2013; Mandell et al. 2013; Swain et al. 2013; Wakeford et al. 2013; Knutson et al. 2014a; Kreidberg et al. 2014).”
• TAU-REX I: A NEXT GENERATION RETRIEVAL CODE FOR EXOPLANETARY ATMOSPHERES (2014, neutral): “MCMC routines are commonly used in the field of extrasolar planets (e.g. Ford 2006; Burke et al. 2010; Bakos et al. 2007; Knutson et al. 2007; Cameron et al. 2007; Charbonneau et al. 2009; Bean et al. 2010; Kipping & Bakos 2011; Gregory 2011; Crouzet et al. 2012; Kreidberg et al. 2014).”
• Global Climate and Atmospheric Composition of the Ultra-hot Jupiter WASP-103b from HST and Spitzer Phase Curve Observations (2018, methodology): “We infer a range in metallicity of 23+29−13× solar, somewhat higher than expected based on Jupiter’s metal enrichment (3 − 5× solar; Wong et al. 2004) and the trend toward decreasing metallicity with increasing planet mass observed for the Solar System and exoplanets (e.g. Kreidberg et al. 2014a).”
• H− Opacity and Water Dissociation in the Dayside Atmosphere of the Very Hot Gas Giant WASP-18b (2018, methodology): “This is surprising for such massive gas giants, as their expected formation channels imply that their metallicities should be close to their host stars’, as observed in their cooler counterparts (e.g., Kreidberg et al. 2014b; Benneke 2015; Line et al. 2016).”
• CHARACTERIZING TRANSITING EXOPLANET ATMOSPHERES WITH JWST (2015, methodology): “Kreidberg et al. (2014b) provided additional leverage on this relationship via a relatively good constraint on the water abundance in a 2 MJ hot Jupiter.”
• A Population Study of Gaseous Exoplanets (2017, methodology): “Spectral light-curves fitting Finally, we fitted the spectral light-curves using the divide-white method introduced by Kreidberg et al. (2014b), where the white light-curve was used as a comparison source, with the addition of a normalization factor and a wavelength-dependent slope, linear with…”