The GAPS programme at TNG

Aims. We analysed six primary transits of the ultra-hot Jupiter KELT-9 b obtained with the HARPS-N high-resolution spectrograph in the context of the Global Architecture of Planetary Systems (GAPS2) project, to characterise the atmosphere via single-line analysis. Methods. We extracted the transmission spectrum of each individual line by comparing the master out-of-transit spectrum with the in-transit spectra and computing the weighted average of the tomography in the planet reference frame. We corrected for the centre-to-limb variation and the Rossiter-McLaughlin effect by modelling the region of the star disc obscured by the planet during the transit and subtracting it from the master-out spectrum. Results. We detected all six observable lines of the Balmer series within the HARPS-N wavelength range, from H α to H ζ , with a significance exceeding 5 σ . We also focussed on metal species, detecting Na I , Ca I , Ca II , Fe I , Fe II , Mg I , Ti II , Sc II , and Cr II lines. This is the first detection in the atmosphere of an exoplanet of H ϵ and H ζ lines, as well as of individual lines of Sc II and Cr II. Our detections are supported by a comparison with published synthetic transmission spectra of KELT-9b obtained accounting for non-local thermodynamic equilibrium effects. The results underline the presence of a systematic blueshift due to night-side to day-side winds. Conclusions. The single-line analysis allowed us not only to assess the presence of atomic species in the atmosphere of KELT-9 b, but also to further characterise the local stratification of the atmosphere. Coupling the height distribution of the detected species with the velocity shift retrieved, we acknowledged the height distribution of night-side to day-side winds. Moreover, the study of the rotational broadening of the different species supports the prediction of a tidally locked planet rotating as a rigid body.

Authors

Institutions

Publication Details

Journal
Astronomy and Astrophysics
Published
2024-09-05
DOI
https://doi.org/10.1051/0004-6361/202449341
Citations
8
Primary Topic
Atmospheric Ozone and Climate
Type
article
Field-Weighted Citation Impact
3.01

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

The GAPS programme at TNG

A. S. Bonomo, D. Sicilia, Andrea Saba, L. Fossati et al.
8 citations
Astronomy and Astrophysics
Atmospheric Ozone and Climate
3.01
article

The GAPS programme at TNG

A. S. Bonomo, D. Sicilia, Andrea Saba, L. Fossati, R. Claudi, V. Nascimbeni, V. Lorenzi, A. F. Lanza, F. Borsa, Matteo Brogi, S. Benatti, Alessandro Sozzetti, M. Stangret, J. Maldonado, G. Guilluy, G. Mantovan, L. Pino, A. Ghedina, G. Scandariato, G. Andreuzzi, G. Tripodo, C. Knapic, C. Di Maio, A. Bignamini, M. C. D’Arpa, V. Fardella, S. Desidera, Riccardo Spinelli, G. Micela, L. Affer
article en
8 citations

Abstract

Aims. We analysed six primary transits of the ultra-hot Jupiter KELT-9 b obtained with the HARPS-N high-resolution spectrograph in the context of the Global Architecture of Planetary Systems (GAPS2) project, to characterise the atmosphere via single-line analysis. Methods. We extracted the transmission spectrum of each individual line by comparing the master out-of-transit spectrum with the in-transit spectra and computing the weighted average of the tomography in the planet reference frame. We corrected for the centre-to-limb variation and the Rossiter-McLaughlin effect by modelling the region of the star disc obscured by the planet during the transit and subtracting it from the master-out spectrum. Results. We detected all six observable lines of the Balmer series within the HARPS-N wavelength range, from H α to H ζ , with a significance exceeding 5 σ . We also focussed on metal species, detecting Na I , Ca I , Ca II , Fe I , Fe II , Mg I , Ti II , Sc II , and Cr II lines. This is the first detection in the atmosphere of an exoplanet of H ϵ and H ζ lines, as well as of individual lines of Sc II and Cr II. Our detections are supported by a comparison with published synthetic transmission spectra of KELT-9b obtained accounting for non-local thermodynamic equilibrium effects. The results underline the presence of a systematic blueshift due to night-side to day-side winds. Conclusions. The single-line analysis allowed us not only to assess the presence of atomic species in the atmosphere of KELT-9 b, but also to further characterise the local stratification of the atmosphere. Coupling the height distribution of the detected species with the velocity shift retrieved, we acknowledged the height distribution of night-side to day-side winds. Moreover, the study of the rotational broadening of the different species supports the prediction of a tidally locked planet rotating as a rigid body.

Astronomy and AstrophysicsVol. 690
Austrian Academy of Sciences (AT), University of Padua (IT), Arcetri Astrophysical Observatory (IT), Astronomical Observatory of Rome (IT), Trieste Astronomical Observatory (IT), Brera Astronomical Observatory (IT), Space Research Institute (AT), Osservatorio Astrofisico di Torino (IT), Osservatorio Astrofisico di Catania (IT), Osservatorio Astronomico di Palermo (IT), Osservatorio Astronomico di Padova (IT), Telescopio Nazionale Galileo (ES), University College London (GB), University of Turin (IT), National Institute for Astrophysics (IT), University of Palermo (IT)
UK Research and Innovation, University College London, European Commission, Universität Wien, Istituto Nazionale di Astrofisica, Uppsala Universitet, Institut sur la Nutrition et les Aliments Fonctionnels, Science and Technology Facilities Council
Openalex Percentile: Top 8%
Atmospheric Ozone and Climate
3.01
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.