Sodium Absorption from the Exoplanetary Atmosphere of HD 189733b Detected in the Optical Transmission Spectrum

By S. Redfield, M. Endl, W. Cochran, L. Koesterke. 2007

318 citations recorded by the source corpus.

We present the first ground-based detection of sodium absorption in the transmission spectrum of an extrasolar planet. Absorption due to the atmosphere of the extrasolar planet HD 189733b is detected in both lines of the Na I doublet. High spectral resolution observations were taken of 11 transits with the High Resolution Spectrograph (HRS) on the 9.2 m Hobby-Eberly Telescope (HET). The Na I absorption in the transmission spectrum due to HD 189733b is (− 67.2 ± 20.7) × 10−5 deeper in the “narrow” spectral band that encompasses both lines relative to adjacent bands. The 1 σ error includes both random and systematic errors, and the detection is >3 σ. This amount of relative absorption in Na I for HD 189733b is ~3 times larger than that detected for HD 209458b by Charbonneau et al. (2002) and indicates that these two hot Jupiters may have significantly different atmospheric properties.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/1b7026536568e6d0c38155867b78150a33a25b08

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In Astronomy and Astrophysics

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

In Instrumentation

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

Citations in the corpus

• ROTATION AND WINDS OF EXOPLANET HD 189733 b MEASURED WITH HIGH-DISPERSION TRANSMISSION SPECTROSCOPY (2015, background): “…et al. 2010; Jensen et al. 2012) and the prominence of haze (Pont et al. 2008; Sing et al. 2011) masking most of the spectral features in the optical transmission spectrum, except for atomic sodium (Redfield et al. 2008; Huitson et al. 2012; Wyttenbach et al. 2015) and potassium (Pont et al. 2013).”
• Optimal estimation retrievals of the atmospheric structure and composition of HD 189733b from secondary eclipse spectroscopy (2011, methodology): “At visible wavelengths, strong li es of the alkali metal sodium were reported using observations with the high resolution ground spectrograph of theHobby–Eberly Telescope (Redfield et al. 2008), while featureless spectra detected by theHST /ACS (Pont et al. 2008) andHST /STIS (Sing et al. 2011) are ”
• An HST optical-to-near-IR transmission spectrum of the hot Jupiter WASP-19b: detection of atmospheric water and likely absence of TiO (2013, background): “…with decreasing wavelength, attributed to a scattering signature similar to that of Rayleigh scattering (Lecavelier Des Etangs et al. 2008; Pont et al. 2008; Sing et al. 2011a), where all but the narrow cores of the lines are obscured (Redfield et al. 2008; Jensen et al. 2011; Huitson et al. 2012).”
• C/O RATIO AS A DIMENSION FOR CHARACTERIZING EXOPLANETARY ATMOSPHERES (2012, background): “…al. 2002, Vidal Madjar et al. 2004, Tinetti et al. 2007, Swain et al. 2008, 2012; cf Gibson et al. 2011, Bueaulieu et al. 2008, Desert et al. 2009, Redfield et al. 2008, Madhusudhan & Seager 2009, Sing et al. 2011, Bean et al. 2010, Crossfield et al. 2012, Berta et al. 2012), thermal phase curves…”
• MULTIWAVELENGTH CONSTRAINTS ON THE DAY–NIGHT CIRCULATION PATTERNS OF HD 189733b (2008, background): “Observations of the planet’s optical transmission spectrum (Pont et al. 2008; Redfield et al. 2008) suggest that it may have a haze layer that is reducing the depth of the observed absorption features (for a more detailed discussion of this effect see Fortney 2005).”
• Evaporation of the planet HD 189733b observed in H I Lyman-α (2010, background): “Sodium has been detected in the planet’s atmosphere by ground-based observations (Redfield et al. 2008).”
• CAN TiO EXPLAIN THERMAL INVERSIONS IN THE UPPER ATMOSPHERES OF IRRADIATED GIANT PLANETS? (2009, background): “The sodium feature has been seen in the transit spectra of both HD 209458b (Charbonneau et al. 2002; Désert et al. 2008) and HD 189733b (Redfield et al. 2008).”
• Hubble Space Telescope STIS Optical Transit Transmission Spectra of the Hot Jupiter HD 209458b (2008, background): “Ground based spectroscopic measurements, such as the Na detected in HD189733b (Redfield et al. 2008), require airmass corrections and are only sensitive to the Na D line cores where the atmospheric atomic Na in HD209458b is substantially depleted.”
• HST hot-Jupiter transmission spectral survey: detection of potassium in WASP-31b along with a cloud deck and Rayleigh scattering (2014, methodology): “…backed up by observations, both from the detection of Na (Charbonneau et al. 2002; Jensen et al. 2011; Nikolov et al. 2014b; Huitson et al. 2012; Redfield et al. 2008; Sing et al. 2008, 2012; Zhou & Bayliss 2012) and K (Sing et al. 2011a) atoms as well as the generally low albedos found in many…”
• TRANSMISSION SPECTRA OF THREE-DIMENSIONAL HOT JUPITER MODEL ATMOSPHERES (2009, methodology): “For the transmission spectrum, optical data have been published by Pont et al. (2008) and Redfield et al. (2008), near infrareddata by Swain et al. (2008) and Sing et al. (2009), and 3.6 and 5.8 µm IRAC mid-infrared data by Beaulieu et al. (2008) and Ehrenreich et al. (2007)—thisSpitzer data was…”
• CHEMISTRY OF SILICATE ATMOSPHERES OF EVAPORATING SUPER-EARTHS (2009, background): “Sodium has already been detected in the atmospheres of two giant exoplanets HD209458b and HD189733b (Charbonneau et al. 2002, Redfield et al. 2008), so we are hopeful that similar techniques may also observe Na in the atmospheres of the hot superEarths.”
• A Population Study of Gaseous Exoplanets (2017, background): “…detections of atmospheric signatures in extrasolar planet atmospheres (e.g. Charbonneau et al. 2002; Richardson et al. 2007; Tinetti et al. 2007; Grillmair et al. 2008; Knutson et al. 2008; Redfield et al. 2008; Swain et al. 2008) and are rapidly entering the era of comparative exoplanetology.”
• DETECTION OF AN ATMOSPHERE AROUND THE SUPER-EARTH 55 CANCRI E (2015, background): “Using the transit technique, many teams have discovered molecular features in the atmospheres of exoplanets, both from the ground (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.…”
• Transit spectrophotometry of the exoplanet HD189733b. I. Searching for water but finding haze with HST NICMOS (2009, background): “From the ground, Redfield et al. (2008) detected strong Na absorption in the core of the doublet.”
• The prevalence of dust on the exoplanet HD 189733b from Hubble and Spitzer observations (2012, background): “The signature of Rayleigh scattering (Pont et al. 2008; Sing et al. 2011) and the sodium doublet (Redfield et al. 2008; Huitson et al. 2012) have been detected in the UV and visible.”
• Hubble Space Telescope transmission spectroscopy of the exoplanet HD 189733b: high‐altitude atmospheric haze in the optical and near‐ultraviolet with STIS (2011, background): “…sodium wings (e.g. Fortney et al. 2010), though there is good evidence that the sodium line core is present both from ground based measurements (Redfield et al. 2008) as well as our G750M measurements (Huitson, Sing, in prep), which indicates that either the sodium abundance is much lower in…”