Exoplanetology: Exoplanets & Exomoons

TOI-512: Super-Earth Transiting a K-type Star Discovered by TESS and ESPRESSO

By Keith Cowing
Status Report
astro-ph.EP
February 21, 2025
Filed under , , , , , , ,
TOI-512: Super-Earth Transiting a K-type Star Discovered by TESS and ESPRESSO
TESS target pixel files for sector 6 tpfplotter (Aller et al. 2020; the code is publicly available at www.github.com/jlillo/tpfplotter). Orange squares identify the aperture masks used to extract the light curve. Sources cross-matched with the Gaia DR3 catalog are indicated by red dots, whose sizes are scaled with their relative magnitude, compared to that of TOI-512. The pixel scale is 21′′ pixel−1

One of the goals of the ESPRESSO guaranteed time observations (GTOs) at the ESO 8.2m telescope is to follow up on candidate planets from transit surveys such as the TESS mission.

High-precision radial velocities are required to characterize small exoplanets. Aims. We intend to confirm the existence of a transiting super-Earth around the bright (V=9.74) K0-type star TOI-512 (TIC 119292328) and provide a characterization.

Combining photometric data from TESS and 37 high-resolution spectroscopic observations from ESPRESSO in a joint Markov chain Monte Carlo analysis, we determined the planetary parameters of TOI-512b and characterized its internal structure. We find that TOI-512b is a super-Earth, with a radius of 1.54±0.10 R⊕ and mass of 3.57+0.53−0.55~M⊕, on a 7.19+7⋅10−5−6.1⋅10−5 day orbit.

This corresponds to a bulk density of 5.62+1.59−1.28 g cm−3. Our interior structure analysis presents a small inner core representing 0.13+0.13−0.11 of the solid mass fraction for the planet, surrounded by a mantle with a mass fraction of 0.69+0.20−0.22, and an upper limit of the water layer of 0.16. The gas mass below 10−8.93 indicates a very small amount of gas on the planet.

We find no evidence of the second candidate found by the TESS pipeline, TOI-512.02, neither in TESS photometry, nor in the ESPRESSO radial velocities. The low stellar activity makes it an interesting transmission spectroscopy candidate for future-generation instruments.

J. Rodrigues, S.C. Barros, N.C. Santos, J. Davoult, M. Attia, A. Castro-González, S.G. Sousa, O.D.S. Demangeon, M.J. Hobson, D. Bossini, C. Ziegler, J.P. Faria, V. Adibekyan, C. Lovis, B. Lavie, M. Damasso, A.M. Silva, A. Suárez Mascareño, F. Pepe, F. Bouchy, Y. Alibert, J.I. González Hernández, A. Sozzetti, C. Allende Prieto, S. Cristiani, E. Palle, V. D’Odorico, D. Ehrenreich, P. Figueira, K.G. Stassun, R. Génova Santos, G. Lo Curto, C.J.A.P. Martins, A. Mehner, G. Micela, P. Molaro, N.J. Nunes, E. Poretti, R. Rebolo, S. Udry, M.R. Zapatero Osorio

Comments: Accepted for publication in A&A, 12 pages, 10 main figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2502.14472 [astro-ph.EP] (or arXiv:2502.14472v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2502.14472
Focus to learn more
Submission history
From: José Rodrigues
[v1] Thu, 20 Feb 2025 11:50:52 UTC (12,142 KB)
https://arxiv.org/abs/2502.14472
Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

Follow on Twitter
MORE FROM Exoplanetology: Exoplanets & Exomoons