WATER, METHANE, AND CARBON DIOXIDE PRESENT IN THE DAYSIDE SPECTRUM OF THE EXOPLANET HD 209458b

By M. Swain, Giovanna Tinetti, G. Vasisht, P. Deroo, C. Griffith, J. Bouwman, Pin Chen, Yuk L. Yung, Adam Burrows, Linda R. Brown and 4 more. 2009

222 citations recorded by the source corpus.

Using the NICMOS instrument on the Hubble Space Telescope, we have measured the dayside spectrum of HD 209458b between 1.5 and 2.5 μm. The emergent spectrum is dominated by features due to the presence of methane (CH4) and water vapor (H2O), with smaller contributions from carbon dioxide (CO2). Combining this near-infrared spectrum with existing mid-infrared measurements shows the existence of a temperature inversion and confirms the interpretation of previous photometry measurements. We find a family of plausible solutions for the molecular abundance and detailed temperature profile. Observationally resolving the ambiguity between abundance and temperature requires either (1) improved wavelength coverage or spectral resolution of the dayside emission spectrum or (2) a transmission spectrum where abundance determinations are less sensitive to the temperature structure.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/894e16d3d4a7bf020301529c1068ccd570736723

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In Astronomy and Astrophysics

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

In Instrumentation

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

Citations in the corpus

• A SYSTEMATIC RETRIEVAL ANALYSIS OF SECONDARY ECLIPSE SPECTRA. II. A UNIFORM ANALYSIS OF NINE PLANETS AND THEIR C TO O RATIOS (2013, methodology): “Secondary eclipse observations have been made with a variety of instruments including HSTNICMOS (Swain et al. 2009), Spitzer IRAC (Deming et al. 2006; Charbonneau et al. 2008; Knutson et al. 2009; 2012; Agol et al. 2012), MIPS (Knutson et al. 2009; Charbonneau et al. 2008), and IRS (Grillmair et…”
• An Accurate, Extensive, and Practical Line List of Methane for the HITEMP Database (2020, background): “…below ∼1300 K (Burrows & Sharp 1999), yet observations of CH4 have only been reported in the spectra of five exoplanets to date: HD 189733b (Swain et al. 2008), HD 209458b (Swain et al. 2009), XO-1b (Tinetti et al. 2010), HR 8799b (Barman et al. 2015) and 51 Eridani b (Macintosh et al. 2015).”
• A CORRELATION BETWEEN STELLAR ACTIVITY AND HOT JUPITER EMISSION SPECTRA (2010, background): “Indeed, the detection of an excess of CO2 in the atmosphere of the hot Jupiter HD 189733b (Swain et al. 2009a) indicates that non-equilibrium chemistry may play an important role in these atmospheres.”
• 3.6 AND 4.5 μm PHASE CURVES AND EVIDENCE FOR NON-EQUILIBRIUM CHEMISTRY IN THE ATMOSPHERE OF EXTRASOLAR PLANET HD 189733b (2012, background): “…include an additional grey absorber at low pressures, which is required to reproduce the high-altitude temperature inversions observed in the atmospheres of a subset of hot Jupiters such as HD 209458b (e.g., Burrows et al. 2007; Knutson et al. 2008; Swain et al. 2009; Madhusudhan & Seager 2010).”
• A NEW APPROACH TO ANALYZING HST SPATIAL SCANS: THE TRANSMISSION SPECTRUM OF HD 209458 b (2015, methodology): “…with ground-based and space-based instruments (e.g. Charbonneau et al. 2002; Vidal-Madjar et al. 2003; Redfield et al. 2008; Snellen et al. 2008; Swain et al. 2009a,b; Linsky et al. 2010; Swain et al. 2010; Tinetti et al. 2010; Crouzet et al. 2012; Majeau et al. 2012; Waldmann et al. 2012;…”
• HD 209458b in new light: evidence of nitrogen chemistry, patchy clouds and sub-solar water (2017, background): “Various carbon and oxygen-rich molecular species have been claimed in its atmosphere, including H2O, CH4, CO and CO2 (Barman 2007; Swain et al. 2009; Madhusudhan & Seager 2009; Snellen et al. 2010; Deming et al. 2013).”
• LYα TRANSIT SPECTROSCOPY AND THE NEUTRAL HYDROGEN TAIL OF THE HOT NEPTUNE GJ 436b (2014, background): “…at IR and optical wavelengths has led to the discovery of Na I, H2O, CH4, and CO (Charbonneau et al. 2002; Tinetti et al. 2007; Swain et al. 2008; Swain et al. 2009) in the atmospheres of exoplanets, shifting the emphasis of exoplanet studies toward detecting and characterizing their…”
• THE EFFECTS OF SNOWLINES ON C/O IN PLANETARY ATMOSPHERES (2011, background): “…HD 189733B are candidates to have atmospheres originating from mainly gas accretion beyond both the H2O and CO2 snowlines (Madhusudhan et al. 2011; Swain et al. 2009, 2010), pending confirmation of the reported C/O ratios and C/H ratios and theoretical confirmation of that the observed…”
• Exoplanet Atmospheres: Physical Processes (2010, background): “Some initial indications from Spitzer spectroscopy that water absorption was absent (Richardson et al. 2007; Grillmair et al. 2007) were superceded by higher S/N data that clearly showed water absorption (Grillmair et al. 2008; Swain et al. 2008, Swain et al 2009a).”
• A TEMPERATURE AND ABUNDANCE RETRIEVAL METHOD FOR EXOPLANET ATMOSPHERES (2009, methodology): “In addition, we also use the photometric observations of Charbonneau et al. (2008), and the spectrophotometric observations of Swain et al. (2009a) to place complementary constraints 4.”
• DISEQUILIBRIUM CARBON, OXYGEN, AND NITROGEN CHEMISTRY IN THE ATMOSPHERES OF HD 189733b AND HD 209458b (2011, methodology): “The fact that the predicted infrared eclipse depths from our dayside-average model seem to be uniformly too small compared to observations, combined with the low dayside CH4 abundance inferred by Swain et al. (2009a); Madhusudhan & Seager (2009), suggest a scenario in which the dayside-vs.”
• The escape of heavy atoms from the ionosphere of HD209458b. I. A photochemical–dynamical model of the thermosphere (2012, background): “Visible and infrared observations have also revealed the101 presence of Na, H2O, CH4, and CO2 in the lower atmosphere (Charbonneau102 et al., 2002; Knutson et al., 2008; Swain et al., 2009).”
• A SYSTEMATIC RETRIEVAL ANALYSIS OF SECONDARY ECLIPSE SPECTRA. I. A COMPARISON OF ATMOSPHERIC RETRIEVAL TECHNIQUES (2013, methodology): “55 61 peratures and compositions (see e.g., Charbonneau et al. 2005; Tinetti et al. 2007; 2010; Grillmair et al. 2007; 2008; Swain et al. 2009a; 2009b; Madahusudhan & Seager 2009; Stevenson et al. 2011; Madhusudhan et al. 2011; Lee et al. 2012; Line et al. 2012).”
• A chemical model for the atmosphere of hot Jupiters (2012, methodology): “Some observational data are superimposed on the spectra (Charbonneau et al. 2008; Grillmair et al. 2008; Swain et al. 2009b, for emission spectrum) and (Knutson et al. 2007, 2009; Swain et al. 2008b; Beaulieu et al. 2008; Sing et al. 2009; Désert et al. 2009; Agol et al. 2010, for transmission…”
• DETECTION OF AN ATMOSPHERE AROUND THE SUPER-EARTH 55 CANCRI E (2015, unknown): “…(e.g. Redfield et al. 2008; Swain et al. 2010; Waldmann et al. 2012; Snellen et al. 2008, 2010, 2014; Bean et al. 2010, 2013) and from space (e.g. Charbonneau et al. 2002, 2005; Deming et al. 2005, 2011; Knutson et al. 2007, 2008; Tinetti et al. 2007b, 2010; Swain et al. 2008, 2009a,b, 2013).”