Detection of Fe and Ti on the dayside of the ultrahot Jupiter MASCARA-1b with CARMENES

¹ Department of Astronomy, University of Science and Technology of China, Hefei 230026, PR China
e-mail: yanfei@ustc.edu.cn
² Institut für Astrophysik und Geophysik, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
³ Ludwig-Maximilians-Universität, Universitäts-Sternwarte München, Scheinerstr. 1, 81679, Munich, Germany
⁴ Exzellenzcluster Origins, Boltzmannstraße 2, 85748 Garching, Germany
⁵ Instituto de Astrofísica de Canarias (IAC), Vía Lactea s/n, 38200 La Laguna, Tenerife, Spain
⁶ Departamento de Astrofísica, Universidad de La Laguna, 38026 La Laguna, Tenerife, Spain
⁷ Instituto de Astrofísica de Andalucía – CSIC, Glorieta de la Astronomía s/n, 18008 Granada, Spain
⁸ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
⁹ Landessternwarte, Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, 69117 Heidelberg, Germany
¹⁰ CAS Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, PR China
¹¹ CAS Center for Excellence in Comparative Planetology, Hefei 230026, PR China
¹² INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122, Padova, Italy
¹³ Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany
¹⁴ Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
¹⁵ Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, c/ de Can Magrans s/n, 08193 Bellaterra, Barcelona, Spain
¹⁶ Institut d’Estudis Espacials de Catalunya (IEEC), 08034 Barcelona, Spain
¹⁷ Centro de Astrobiología (CSIC-INTA), ESAC, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain
¹⁸ Centro Astronónomico Hispano-Alemán (CSIC–Junta de Andalucía), Observatorio Astronónomico de Calar Alto, Sierra de los Filabres, 04550 Gérgal, Almería, Spain
¹⁹ Departamento de Física de la Tierra y Astrofísica and IPARCOS-UCM (Instituto de Física de Partículas y del Cosmos de la UCM), Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain

Received: 7 March 2024
Accepted: 17 April 2024

Abstract

Ultrahot Jupiters are a type of gaseous exoplanet that orbit extremely close to their host star, resulting in significantly high equilibrium temperatures. In recent years, high-resolution emission spectroscopy has been broadly employed in observing the atmospheres of ultrahot Jupiters. We used the CARMENES spectrograph to observe the high-resolution spectra of the dayside hemisphere of MASCARA-1b in both visible and near-infrared. Through cross-correlation analysis, we detected signals of Fe I and Ti I. Based on these detections, we conducted an atmospheric retrieval and discovered the presence of a strong inversion layer in the planet’s atmosphere. The retrieved Ti and Fe abundances are broadly consistent with solar abundances. In particular, we obtained a relative abundance of [Ti/Fe] as −1.0 ± 0.8 under the free retrieval and −0.4_−0.8^+0.5 under the chemical equilibrium retrieval, suggesting the absence of significant titanium depletion on this planet. Furthermore, we considered the influence of planetary rotation on spectral line profiles. The resulting equatorial rotation speed was determined to be 4.4_−2.0^+1.6 km s⁻¹, which agrees with the rotation speed induced by tidal locking.