HD 20329b: An ultra-short-period planet around a solar-type star found by TESS

• Published in: arXiv.org
• Main Authors: Murgas, F, Nowak, G, Masseron, T, Parviainen, H, Luque, R, Pallé, E, Korth, Judith, Carleo, I, Csizmadia, Sz, Esparza-Borges, E, Alqasim, Ahlam, Cochran, William D, Dai, Fei, Deeg, Hans J, Gandolfi, D, Goffo, Elisa, Kabáth, Petr, Lam, K W F, Livingston, John, Muresan, Alexandra, Osborne, H L M, Persson, Carina M, Serrano, L M, Smith, Alexis M S, Vincent Van Eylen, Orell-Miquel, J, Hinkel, Natalie R, Galán, D, Puig-Subirà, M, Stangret, M, Fukui, A, Kagetani, T, Narita, N, Ciardi, David R, Boyle, Andrew W, Ziegler, Carl, Briceño, César, Law, Nicholas, Mann, Andrew W, Jenkins, Jon M, Latham, David W, Quinn, Samuel N, Ricker, G, Seager, S, Shporer, Avi, Ting, Eric B, Vanderspek, R, Winn, Joshua N
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 07.11.2022
• Subjects: Doppler effect; Extrasolar planets; Light curve; Orbits; Physical properties; Physics - Earth and Planetary Astrophysics; Physics - Solar and Stellar Astrophysics; Radial velocity; Spectrographs; Transit
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2211.02547

We used TESS light curves and HARPS-N spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate found around the star HD 20329 (TOI-4524). We performed a joint fit of the light curves and radial velocity time series to measure the mass, radius, and orbital parameters of the candidate. We confirm and characterize HD 20329b, an ultra-short-period (USP) planet transiting a solar-type star. The host star (HD 20329, \(V = 8.74\) mag, \(J = 7.5\) mag) is characterized by its G5 spectral type with \(\mathrm{M}_\star= 0.90 \pm 0.05\) M\(_\odot\), \(\mathrm{R}_\star = 1.13 \pm 0.02\) R\(_\odot\), and \(\mathrm{T}_{\mathrm{eff}} = 5596 \pm 50\) K; it is located at a distance \(d= 63.68 \pm 0.29\) pc. By jointly fitting the available TESS transit light curves and follow-up radial velocity measurements, we find an orbital period of \(0.9261 \pm (0.5\times 10^{-4})\) days, a planetary radius of \(1.72 \pm 0.07\) \(\mathrm{R}_\oplus\), and a mass of \(7.42 \pm 1.09\) \(\mathrm{M}_\oplus\), implying a mean density of \(\rho_\mathrm{p} = 8.06 \pm 1.53\) g cm\(^{-3}\). HD 20329b joins the \(\sim\)30 currently known USP planets with radius and Doppler mass measurements.