Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b

By M. Brogi, Remco J. de Kok, J. Birkby, H. Schwarz, I. Snellen. 2014

134 citations recorded by the source corpus.

(Abridged) In recent years, ground-based high-resolution spectroscopy has become a powerful tool for investigating exoplanet atmospheres. It allows the robust identification of molecular species, and it can be applied to both transiting and non-transiting planets. Radial-velocity measurements of the star HD 179949 indicate the presence of a giant planet companion in a close-in orbit. Here we present the analysis of spectra of the system at 2.3 micron, obtained at a resolution of R~100,000, during three nights of observations with CRIRES at the VLT. We targeted the system while the exoplanet was near superior conjunction, aiming to detect the planet's thermal spectrum and the radial component of its orbital velocity. We detect molecular absorption from carbon monoxide and water vapor with a combined S/N of 6.3, at a projected planet orbital velocity of K_P = (142.8 +- 3.4) km/s, which translates into a planet mass of M_P = (0.98 +- 0.04) Jupiter masses, and an orbital inclination of i = (67.7 +- 4.3) degrees, using the known stellar radial velocity and stellar mass. The detection of absorption features rather than emission means that, despite being highly irradiated, HD 179949 b does not have an atmospheric temperature inversion in the probed range of pressures and temperatures. Since the host star is active (R_HK > -4.9), this is in line with the hypothesis that stellar activity damps the onset of thermal inversion layers owing to UV flux photo-dissociating high-altitude, optical absorbers. Finally, our analysis favors an oxygen-rich atmosphere for HD 179949 b, although a carbon-rich planet cannot be statistically ruled out based on these data alone.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/3f37a2c8ab4a1b24f594c7da5665067a7cafe76b

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. A. Showman
4. M. Line
5. M. Marley
6. V. Parmentier
7. Laura Kreidberg
8. J. D'esert

In Instrumentation

1. N. Madhusudhan
2. Jon Fortney
3. A. Showman
4. M. Line
5. V. Parmentier
6. Laura Kreidberg
7. M. Marley
8. J. D'esert

In Statistical and Nonlinear Physics

1. N. Madhusudhan
2. Jon Fortney
3. M. Marley
4. V. Parmentier
5. M. Line
6. A. Showman
7. Laura Kreidberg
8. J. D'esert

Citations in the corpus

• The habitability of Proxima Centauri b II. Possible climates and Observability (2016, background): “Such a planet-star disentangling was already achieved for non-transiting unresolved hot Jupiters with a contrast of ∼ 10−4 (Brogi et al. 2014).”
• A DETECTION OF WATER IN THE TRANSMISSION SPECTRUM OF THE HOT JUPITER WASP-12b AND IMPLICATIONS FOR ITS ATMOSPHERIC COMPOSITION (2015, background): “…of the carbon-to-oxygen ratio (C/O) and absolute water abundance, which in some cases rival our knowledge of those quantities for the Solar System planets (e.g. Madhusudhan et al. 2011b; Konopacky et al. 2013; Line et al. 2014; Kreidberg et al. 2014a; Brogi et al. 2014; Madhusudhan et al. 2014b).”
• ROTATION AND WINDS OF EXOPLANET HD 189733 b MEASURED WITH HIGH-DISPERSION TRANSMISSION SPECTROSCOPY (2015, methodology): “Residual telluric absorption is also disfavored by previous work on dayside spectra of HD 179949 b (Brogi et al. 2014), which has shown no spurious cross-correlation from the cold methane in the Earth’s atmosphere.”
• Extremely Irradiated Hot Jupiters: Non-oxide Inversions, H− Opacity, and Thermal Dissociation of Molecules (2018, methodology): “…resolution by spectroscopically separating the planet’s flux contribution from its host star and telluric lines in a way very similar to techniques used to detect spectroscopic binary stars (e.g., Snellen et al. 2008; Birkby et al. 2013; de Kok et al. 2013; Brogi et al. 2014; Schwarz et al. 2015).”
• ExoMol molecular line lists XXX: a complete high-accuracy line list for water (2018, background): “Some of these exoplanet observations require high accuracy laboratory data (Birkby et al. 2013; Brogi et al. 2014).”
• From thermal dissociation to condensation in the atmospheres of ultra hot Jupiters: WASP-121b in context (2018, background): “This would introduce further complexity when trying to cross-correlate the high-resolution spectrum of a planet with a template spectrum (e.g., Brogi et al. 2014).”
• Exoplanetary Atmospheres: Key Insights, Challenges, and Prospects (2019, background): “ge www.annualreviews.org Exoplanetary Atmospheres 19 Table 1 { Continued from previous page Chemical Species Planet (References) High-resolution Doppler Spectroscopy H 2O 51 Peg b (25), HD 179949 b (39), HD 189733b (24), HD 209458b (101) CO ˝Bootis b (37), HD 209458b (251), 51 Peg b (38), HD 179949”