Detailed spectroscopic and photometric analysis of the remarkable planet-hosting wide binary system HD 202772A/B
Year: 2025
Type: article
Abstract: ABSTRACT We conducted a detailed spectroscopic and photometric characterization of the planet-hosting wide binary HD 202772A/B. No planet has been detected around HD 202772B, whereas HD 202772A, more evolved than its companion and near the end of its main-sequence (MS) phase, hosts a transiting hot Jupiter. The system has one of the hottest components ($T_{\mathrm{eff}; A} \sim 6440$ K) and one of the largest surface gravity differences between components ($\Delta \log g_{A-B} \sim 0.4$ dex) among MS planet-hosting wide binaries. Using a global fit including our stellar parameters, radial velocities, and new data from the Transiting Exoplanet Survey Satellite (TESS), we derive refined properties of the planet orbiting HD 202772A, finding it to be the most irradiated hot Jupiter known in a wide binary. We also constrain the presence of additional transiting planets around HD 202772A and new transiting planets around HD 202772B using TESS photometry. We derive high-precision, strictly differential abundances for 27 species based on Gemini-GRACES spectra. HD 202772A shows lower lithium abundance (by 0.45 dex) relative to B, consistent with their stellar parameter differences. We also detect a small but significant enhancement in refractory elements in HD 202772A, particularly those with condensation temperatures above 1400 K (+0.018 $\pm$ 0.004 dex). We explored several scenarios to explain the observed chemical anomalies. Our analysis suggests that rocky planet engulfment, primordial inhomogeneities, and $\delta$ Scuti-related effects are unlikely to fully account for the chemical pattern. Instead, the differences observed in certain refractory elements might support atomic diffusion as the most plausible explanation.
Authors: Emiliano Jofré, Yilen Gómez Maqueo Chew, Romina Petrucci, Carlos Saffe, Jhon Yana Galarza, Paula Miquelarena, María Paula Ronco, Matías Cerioni, Camila Zuloaga, Eder Martioli, Francesca Faedi, Cintia Martínez, Leila Saker, Jorge Meléndez, Matías Flores Trivigno, Leslie Hebb, Rodrigo Díaz, Luciano García
Institutions: Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba, Argentine National Observatory, Universidad Nacional Autónoma de México, National University of San Juan, Instituto de Ciencias Astronómicas, de la Tierra y del Espacio, University of Concepción, Carnegie Institution for Science, Carnegie Observatories, Instituto de Astrofísica de La Plata, Universidad Nacional de La Plata, Instituto de Astronomía Teórica y Experimental, Laboratório Nacional de Astrofísica, University of Leicester, Universidade de São Paulo, Hobart and William Smith Colleges, National University of General San Martín, International Center for Advanced Studies
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,046
Funders: National Science Foundation, National Aeronautics and Space Administration, California Institute of Technology, University of Hawai'i, National Research Council Sri Lanka, Consejo Nacional de Investigaciones Científicas y Técnicas, Ministerio de Ciencia, Tecnología e Innovación Productiva, Ministério da Ciência, Tecnologia e Inovação, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Korea Astronomy and Space Science Institute, Ministère de l'Education Nationale, de l'Enseignement Supérieur et de la Recherche, Centre National de la Recherche Scientifique, Fundação de Amparo à Pesquisa do Estado de Minas Gerais, Universidad Nacional Autónoma de México, Agencia Nacional de Investigación y Desarrollo, Ames Research Center, Science Mission Directorate, Natural Sciences and Engineering Research Council of Canada, Agencia Nacional de Promoción Científica y Tecnológica, Institut national des sciences de l'Univers
OpenAlex ID: W4415945916