Exoplanet atmospheres at high resolution through a modest-size telescope. Fe II in MASCARA-2b and KELT-9b with FIES on the Nordic Optical Telescope

Abstract

Ground-based, high-resolution spectrographs are providing us with an unprecedented view of the dynamics and chemistry of the atmospheres of planets outside the Solar System. While there is a large number of stable and precise high-resolution spectrographs on modest-size telescopes, it is the spectrographs at observatories with apertures larger than 3.5 metres that dominate the atmospheric follow-up of exoplanets. In this work, we explore the potential of characterising exoplanetary atmospheres with FIES, a high-resolution spectrograph at the 2.56 metre Nordic Optical Telescope. We observed two transits of MASCARA-2 b (also known as KELT-20 b) and one transit of KELT-9 b to search for atomic iron, a species that has been recently discovered in both neutral and ionised forms in the atmospheres of these ultra-hot Jupiters using large telescopes. Using a cross-correlation method, we detect a signal of Fe II at the $4.5\sigma$ and $4.0\sigma$ level in the transits of MASCARA-2 b. We also detect Fe II in the transit of KELT-9 b at the $8.5\sigma$ level. Although we do not find any significant Doppler shift in the signal of MASCARA-2 b, we do measure a moderate blueshift (3-6 km/s) of the feature in KELT-9 b, which might be a manifestation of high-velocity winds transporting Fe II from the planetary dayside to the nightside. Our work demonstrates the feasibility of investigating exoplanet atmospheres with FIES, potentially unlocking a wealth of additional atmosphere detections with this and other high-resolution spectrographs mounted on similar-size telescopes.

9 pages, 6 figures, accepted to A&A

References in corpus (25)

• Molecfit: A general tool for telluric absorption correction. I. Method and application to ESO instruments
• The fast spin-rotation of a young extrasolar planet
• A giant planet undergoing extreme ultraviolet irradiation by its hot massive-star host
• Combining high-dispersion spectroscopy (HDS) with high contrast imaging (HCI): Probing rocky planets around our nearest neighbors
• A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b
• Barycentric Corrections at 1 cm/s for precise Doppler velocities
• A solar C/O and sub-solar metallicity in a hot Jupiter atmosphere
• Five carbon- and nitrogen-bearing species in a hot giant planet's atmosphere
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) IV. A spectral inventory of atoms and molecules in the high-resolution transmission spectrum of WASP-121 b
• High-Resolution Spectroscopic Detection of TiO and Stratosphere in the Day-side of WASP-33b
• HELIOS-K 2.0 Opacity Calculator and Open-source Opacity Database for Exoplanetary Atmospheres
• Neutral Iron Emission Lines From The Day-side Of KELT-9b -- The GAPS Programme With HARPS-N At TNG XX
• Titanium oxide and chemical inhomogeneity in the atmosphere of the exoplanet WASP-189b
• KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603
• Decomposing the Iron Cross-Correlation Signal of the Ultra-Hot Jupiter WASP-76b in Transmission using 3D Monte-Carlo Radiative Transfer
• An Atomic Spectral Survey of WASP-76b: Resolving Chemical Gradients and Asymmetries
• An inventory of atomic species in the atmosphere of WASP-121b using UVES high-resolution spectroscopy
• High-resolution Transmission Spectroscopy of MASCARA-2 b with EXPRES
• Confirmation of Iron Emission Lines and Non-detection of TiO on the Dayside of KELT-9b with MAROON-X
• Detection of iron emission lines and a temperature inversion on the dayside of the ultra-hot Jupiter KELT-20b
• Mining the Ultra-Hot Skies of HAT-P-70b: Detection of a Profusion of Neutral and Ionized Species
• CO Detected in CI Tau b: Hot Start Implied by Planet Mass and M${}_K$
• The GAPS programme at TNG XXX. Atmospheric Rossiter-McLaughlin effect and atmospheric dynamics of KELT-20b
• KELT-9 as an eclipsing double-lined spectroscopic binary: a unique and self-consistent solution to the system
• Detection limits of exoplanetary atmospheres with 2-m class telescopes

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• The PEPSI Exoplanet Transit Survey (PETS). II. A Deep Search for Thermal Inversion Agents in KELT-20 b/MASCARA-2 b with Emission and Transmission Spectroscopy
• Unifying High- and Low-resolution Observations to Constrain the Dayside Atmosphere of KELT-20b/MASCARA-2b
• The stable climate of KELT-9b
• An atlas of resolved spectral features in the transmission spectrum of WASP-189 b with MAROON-X
• The GAPS programme at TNG. XLV. HI Balmer lines transmission spectroscopy and NLTE atmospheric modelling of the ultra-hot Jupiter KELT-20b/MASCARA-2b
• Transmission spectroscopy of the lowest-density gas giant: metals and a potential extended outflow in HAT-P-67b
• High-resolution Emission Spectroscopy of the Ultrahot Jupiter KELT-9b: Little Variation in Day- and Nightside Emission Line Contrasts
• The GAPS programme at TNG: TBD. Studies of atmospheric FeII winds in ultra-hot Jupiters KELT-9b and KELT-20b using HARPS-N spectrograph
• Multi-epoch detections of the extended atmosphere and transmission spectra of KELT-9b with a 1.5 m telescope
• Instrumentation prospects for rocky exoplanet atmospheres studies with high resolution spectroscopy
• Probing Na in giant exoplanets with ESPRESSO and 3D NLTE stellar spectra
• Extreme winds on the emerging dayside of an ultrahot Jupiter
• Strong NUV Refractory Absorption and Dissociated Water in the Hubble Transmission Spectrum of the Ultra Hot Jupiter KELT-20 b
• PEPSI Investigation, Retrieval, and Atlas of Numerous Giant Atmospheres (PIRANGA). IV. High-Resolution Phased-Resolved Spectroscopy of The Ultra Hot Jupiter KELT-20 b