Exoplanet atmospheres with GIANO II. Detection of molecular absorption in the dayside spectrum of HD 102195b

Abstract

The study of exoplanetary atmospheres is key to understand the differences between their physical, chemical and dynamical processes. Up to now, the bulk of atmospheric characterization analysis has been conducted on transiting planets. On some sufficiently bright targets, high-resolution spectroscopy (HRS) has also been successfully tested for non-transiting planets. We study the dayside of the non-transiting planet HD 102195b using the GIANO spectrograph mounted at TNG, demonstrating the feasibility of atmospheric characterization measurements and molecular detection for non-transiting planets with the HRS technique using 4-m class telescopes. The Doppler-shifted planetary signal changes on the order of many km/s during the observations, in contrast with the telluric absorption which is stationary in wavelength, allowing us to remove the contamination from telluric lines while preserving the features of the planetary spectrum. The emission signal from HD 102195b's atmosphere is then extracted by cross-correlating the residual spectra with atmospheric models. We detect molecular absorption from water vapor at 4.4$\sigma$ level. We also find convincing evidence for the presence of methane, which is detected at the 4.1$\sigma$ level. The two molecules are detected with a combined significance of 5.3$\sigma$, at a semi-amplitude of the planet radial velocity $K_P=128\pm 6$ km/s. We estimate a planet true mass of $M_P=0.46\pm 0.03M_J$ and orbital inclination between 72.5 and 84.79${}^{\circ }$ (1$\sigma$). Our analysis indicates a non-inverted atmosphere for HD 102195b, as expected given the relatively low temperature of the planet, inefficient to keep TiO/VO in gas phase. Moreover, a comparison with theoretical expectations and chemical model predictions corroborates our methane detection and suggests that the detected $C{H}_4$ and $H_{2}O$ signatures could be consistent with a low C/O ratio.

12 pages, 12 figures, accepted for publication in A&A

References in corpus (15)

• The Gaia mission
• EXOFAST: A fast exoplanetary fitting suite in IDL
• The fast spin-rotation of a young extrasolar planet
• Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b
• Weighing The Non-Transiting Hot Jupiter Tau BOO b
• Discovery of water at high spectral resolution in the atmosphere of 51 Peg b
• SPIRou: the near-infrared spectropolarimeter/high-precision velocimeter for the Canada-France-Hawaii telescope
• The spectrum of hot methane in astronomical objects using a comprehensive computed line list
• The slow spin of the young sub-stellar companion GQ Lupi b and its orbital configuration
• Evidence against a strong thermal inversion in HD 209458 b from high-dispersion spectroscopy
• A new Neptune-mass planet orbiting HD 219828
• Improved parameters of seven Kepler giant companions characterized with SOPHIE and HARPS-N
• Evidence for the Direct Detection of the Thermal Spectrum of the Non-Transiting Hot Gas Giant HD 88133 b
• Planetpol polarimetry of the exoplanet systems 55 Cnc and tau Boo
• Detection of Water Vapor in the Thermal Spectrum of the Non-Transiting Hot Jupiter upsilon Andromedae b

Cited by in corpus (50)

• Detection of Fe I in the atmosphere of the ultra-hot Jupiter WASP-121b, and a new likelihood-based approach for Doppler-resolved spectroscopy
• Five carbon- and nitrogen-bearing species in a hot giant planet's atmosphere
• Where is the Water? Jupiter-like C/H ratio but strong H${}_2$O depletion found on $\tau$ Boötis b using SPIRou
• A New Window into Planet Formation and Migration: Refractory-to-Volatile Elemental Ratios in Ultra-hot Jupiters
• The Solar Neighborhood XLIX: Nine Giant Planets Orbiting Nearby K Dwarfs, and the CHIRON Spectrograph's Radial Velocity Performance
• A He I upper atmosphere around the warm Neptune GJ 3470b
• The atmosphere of HD 209458b seen with ESPRESSO. No detectable planetary absorptions at high resolution
• Molecular Cross Sections for High Resolution Spectroscopy of Super Earths, Warm Neptunes and Hot Jupiters
• High-resolution Transmission Spectroscopy of MASCARA-2 b with EXPRES
• HyDRA-H: Simultaneous Hybrid Retrieval of Exoplanetary Emission Spectra
• Grid of Pseudo-2D Chemistry Models for Tidally-Locked Exoplanets. I. The Role of Vertical and Horizontal Mixing
• Seeing above the Clouds with High Resolution Spectroscopy
• Sulfur Chemistry in the Atmospheres of Warm and Hot Jupiters
• Prospects for Characterizing the Haziest Sub-Neptune Exoplanets with High Resolution Spectroscopy
• The GAPS Programme at TNG XXXVIII. Five molecules in the atmosphere of the warm giant planet WASP-69b detected at high spectral resolution
• Evidence for disequilibrium chemistry from vertical mixing in hot Jupiter atmospheres. A comprehensive survey of transiting close-in gas giant exoplanets with warm-Spitzer/IRAC
• Robustness Measures for Molecular Detections using High-Resolution Transmission Spectroscopy of Exoplanets
• The composition of hot Jupiter atmospheres assembled within chemically evolved protoplanetary discs
• Detection of CO emission lines in the dayside atmospheres of WASP-33b and WASP-189b with GIANO
• Characterizing exoplanetary atmospheres at high resolution with SPIRou: Detection of water on HD 189733 b
• The GAPS Programme at TNG. XXXII. The revealing non-detection of metastable HeI in the atmosphere of the hot Jupiter WASP-80b
• Determining the true mass of radial-velocity exoplanets with Gaia: 9 planet candidates in the brown-dwarf/stellar regime and 27 confirmed planets
• Searching for the origin of the Ehrenreich effect in ultra-hot Jupiters: Evidence for strong C/O gradients in the atmosphere of WASP-76b?
• The GAPS Programme at TNG LV. Multiple molecular species in the atmosphere of HAT-P-11 b and review of the HAT-P-11 planetary system
• Search for TiO and Optical Night-side Emission from the Exoplanet WASP-33b
• A 1.46-2.48 $\mu$m Spectroscopic Atlas of a T6 Dwarf (1060 K) Atmosphere with IGRINS: First Detections of H${}_2$S and H${}_2$, and Verification of H${}_2$O, CH${}_4$, and NH${}_3$ Line Lists
• The role of clouds on the depletion of methane and water dominance in the transmission spectra of irradiated exoplanets
• Auto-Differentiable Spectrum Model for High-Dispersion Characterization of Exoplanets and Brown Dwarfs
• Indications for very high metallicity and absence of methane for the eccentric exo-Saturn WASP-117b
• The GAPS Programme at TNG XXXIII. HARPS-N detects multiple atomic species in emission from the dayside of KELT-20b
• A weak spectral signature of water vapour in the atmosphere of HD 179949 b at high spectral resolution in the L-band
• Exoplanet Volatile Carbon Content as a Natural Pathway for Haze Formation
• DREAM: III.A helium survey in exoplanets on the edge of the hot Neptune desert with GIANO-B@TNG
• A sub-solar metallicity on the ultra-short period planet HIP 65Ab
• Investigating the detectability of hydrocarbons in exoplanet atmospheres with JWST
• Revisiting Radial Velocity Measurements of the K2-18 System with the Line-by-Line Framework
• Discriminating between hazy and clear hot-Jupiter atmospheres with CARMENES
• Experimental characterization of modal noise in multimode fibers for astronomical spectrometers
• Simulating the Multi-Epoch Direct Detection Technique to Isolate the Thermal Emission of the Non-Transiting Hot Jupiter HD187123B
• Instrumentation prospects for rocky exoplanet atmospheres studies with high resolution spectroscopy
• ROME III. The Arecibo Search for Star-Planet Interactions at 5 GHz
• Contrast and Temperature Dependence of Multi-Epoch High-Resolution Cross-Correlation Exoplanet Spectroscopy
• The HITRAN2024 methane update
• Experimental Investigation of the Photochemical Production of Hydrocarbons in Warm Gas Giant Exoplanet Atmospheres
• Reinvestigation of the Multi-Epoch Direct Detections of HD 88133 b and Upsilon Andromedae b
• Detection of CO${}_2$, CO, and H${}_2$O in the atmosphere of the warm sub-Saturn HAT-P-12b
• Primary Velocity and Orbital Phase Effects on Planetary Detectability from Small Epoch Number Data Sets
• DARWEN: Data-driven Algorithm for Reduction of Wide Exoplanetary Networks
• Magnetic Drag and 3-D Effects in Theoretical High-Resolution Emission Spectra of Ultrahot Jupiters: the Case of WASP-76b
• A Large-scale Approach to Modelling Molecular Biosignatures: The Diatomics