Habitable Zones & Global Climate

Three Super-Earths And A Possible Water World From TESS And ESPRESSO

By Keith Cowing
Status Report
June 12, 2024
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Three Super-Earths And A Possible Water World From TESS And ESPRESSO
TESS target pixel files for TOI-260 for sector 3 (left), and for TOI-286 for sector 1 ( right). The remaining sectors are shown in Appendix A. The target star is labelled as 1 and marked by a white cross in each case. All sources from the Gaia DR3 catalogue down to a magnitude contrast of 8 are shown as red circles, with the size proportional to the contrast. The SPOC pipeline aperture is overplotted in shaded red squares. — astro-ph.EP

Since 2018, the ESPRESSO spectrograph at the VLT has been hunting for planets in the Southern skies via the RV method. One of its goals is to follow up candidate planets from transit surveys such as the TESS mission, particularly small planets.

We analyzed photometry from TESS and ground-based facilities, high-resolution imaging, and RVs from ESPRESSO, HARPS, and HIRES, to confirm and characterize three new planets: TOI-260 b, transiting a late K-dwarf, and TOI-286 b and c, orbiting an early K-dwarf.

We also update parameters for the known super-Earth TOI-134 b , hosted by an M-dwarf. TOI-260 b has a 13.475853+0.000013−0.000011 d period, 4.23±1.60M mass and 1.71±0.08R radius. For TOI-286 b we find a 4.5117244+0.0000031−0.0000027 d period, 4.53±0.78M mass and 1.42±0.10R radius; for TOI-286 c, a 39.361826+0.000070−0.000081 d period, 3.72±2.22M mass and 1.88±0.12R radius. For TOI-134 b we obtain a 1.40152604+0.00000074−0.00000082 d period, 4.07±0.45M mass, and 1.63±0.14R radius.

Circular models are preferred for all, although for TOI-260 b the eccentricity is not well-constrained. We compute bulk densities and place the planets in the context of composition models. TOI-260 b lies within the radius valley, and is most likely a rocky planet.

However, the uncertainty on the eccentricity and thus on the mass renders its composition hard to determine. TOI-286 b and c span the radius valley, with TOI-286 b lying below it and having a likely rocky composition, while TOI-286 c is within the valley, close to the upper border, and probably has a significant water fraction.

With our updated parameters for TOI-134 b, we obtain a lower density than previous findings, giving a rocky or Earth-like composition.

M. J. Hobson, F. Bouchy, B. Lavie, C. Lovis, V. Adibekyan, C. Allende Prieto, Y. Alibert, S. C. C. Barros, A. Castro-González, S. Cristiani, V. D’Odorico, M. Damasso, P. Di Marcantonio, X. Dumusque, D. Ehrenreich, P. Figueira, R. Génova Santos, J. I. González Hernández, J. Lillo-Box, G. Lo Curto, C. J. A. P. Martins, A. Mehner, G. Micela, P. Molaro, N. J. Nunes, E. Palle, F. Pepe, R. Rebolo, J. Rodrigues, N. Santos, S. G. Sousa, A. Sozzetti, A. Suárez Mascareño, H. M. Tabernero, S. Udry, M.-R. Zapatero Osorio, D. J. Armstrong, D. R. Ciardi, K. A. Collins, K. I. Collins, M. Everett, D. Gandolfi, S. B. Howell, J. M. Jenkins, J. Kielkopf, J. H. Livingston, M. B. Lund, I. Mireles, G. R. Ricker, R. P. Schwarz, S. Seager, T.-G. Tan, E. B. Ting, J. N. Winn

Comments: 61 pages (of which pp. 24-61 are appendices), 20 figures (main text). Accepted for publication in A&A
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2406.06278 [astro-ph.EP] (or arXiv:2406.06278v1 [astro-ph.EP] for this version)

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Submission history
From: Melissa Hobson
[v1] Mon, 10 Jun 2024 13:57:28 UTC (33,359 KB)

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) 🖖🏻