Exoplanets & Exomoons

Three Short-period Earth-sized Planets Around M dwarfs Discovered By TESS: TOI-5720b, TOI-6008b And TOI-6086b

By Keith Cowing
Status Report
astro-ph.EP
May 13, 2024
Filed under , , , , , , , , , , , ,
Three Short-period Earth-sized Planets Around M dwarfs Discovered By TESS: TOI-5720b, TOI-6008b And TOI-6086b
TESS and ground-based photometric data of TOI-5720 b (left panel), TOI-6008 b (middle panel) and TOI-6086 b (right panel). Top plots show the TESS phased-folded, and other plots show the ground-based phased-folded by filter with best-fitting transit model is superimposed. The light curves are shifted along the y-axis for clarity. TESS target pixel file images of TOI-5720 (left panel) TOI-6008 (middle panel) and TOI-6086 (right panel) observed in Sectors 22, 15 and 25, respectively. The mages are made by the tpfplotter package (Aller et al. 2020). Red dots and red shaded polygons show the position of Gaia DR3 sources and photometric apertures used to extract the photometric measurements, respectively. — astro-ph.EP

One of the main goals of the NASA’s TESS (Transiting Exoplanet Survey Satellite) mission is the discovery of Earth-like planets around nearby M-dwarf stars.

Here, we present the discovery and validation of three new short-period Earth-sized planets orbiting nearby M-dwarfs: TOI5720 b, TOI-6008 b and TOI-6086 b. We combined TESS data, ground-based multi-color light curves, ground-based optical and near-infrared spectroscopy, and Subaru/IRD RVs data to validate the planetary candidates and constrain the physical parameters of the systems.

In addition, we used archival images, high-resolution imaging, and statistical validation techniques to support the planetary validation. TOI-5720 b is a planet with a radius of Rp = 1.09 ± 0.07 R orbiting a nearby (23 pc) M2.5 host, with an orbital period of P = 1.4344555 ± 0.0000036 days. It has an equilibrium temperature of Teq = 708 ± 19 K (assuming a null albedo) and an incident flux of S p = 41.7 ± 4.5 S ⊕.

TOI-6008 b has a period of P = 0.8574347 ± 0.0000424 day, a radius of Rp = 1.03 ± 0.05 R, an equilibrium temperature of Teq = 707 ± 19 K and an incident flux of Sp = 41.5 ± 4.5 S. The host star (TOI-6008) is a nearby (36 pc) M5 with an effective temperature of Teff = 3075 ± 75 K. Based on the RV measurements collected with Subaru/IRD, we set a 3σ upper limit of Mp < 4M, thus ruling out a star or brown dwarf as the transiting companion.

TOI-6086 b orbits its nearby (31 pc) M3 host star (Teff = 3200 ± 75 K) every 1.3888725 ± 0.0000827 days, and has a radius of Rp = 1.18 ± 0.07 R, an equilibrium temperature of Teq = 634 ± 16 K and an incident flux of Sp = 26.8 ± 2.7 S.

Additional high precision radial velocity measurements are needed to derive the planetary masses and bulk densities, and to search for additional planets in the systems. Moreover, short-period earth-sized planets orbiting around nearby M-dwarfs are suitable targets for atmospheric characterization with the James Webb Space Telescope ( JWST) through transmission and emission spectroscopy, and phase curve photometry

TESS target pixel file images of TOI-5720 (top panel) TOI-6008 (middle panel) and TOI-6086 (bottom panel) observed in Sectors 22, 15 and 25, respectively. The mages are made by the tpfplotter package (Aller et al. 2020). Red dots and red shaded polygons show the position of Gaia DR3 sources and photometric apertures used to extract the photometric measurements, respectively. — astro-ph.EP

K. Barkaoui, R.P. Schwarz, N. Narita, P. Mistry, C. Magliano, T. Hirano, M. Maity, A.J. Burgasser, B.V. Rackham, F. Murgas, F.J. Pozuelos, K.G. Stassun, M.E. Everett, D.R. Ciardi, C. Lamman, C. Aganze, E. Esparza-Borges, K.A. Collins, G. Covone, J. de Leon, M. D’evora-Pajares, J. de Wit, Izuru Fukuda, A. Fukui, R. Gerasimov, M. Gillon, Y. Hayashi, S.B. Howell, M. Ikoma, K. Ikuta, J.M. Jenkins, P.R. Karpoor, Y. Kawai, T. Kimura, T. Kotani, D.W. Latham, M. Mori, E. Pallé, H. Parviainen, Y.G. Patel, G. Ricker, H.M. Relles, A. Shporer, S. Seager, E. Softich, G. Srdoc, M. Tamura, C.A. Theissen, J.D. Twicken, R. Vanderspek, N. Watanabe, C.N. Watkins, J.N. Winn, B. Wohler

Comments: 27 pages, 21 figures, Accepted for publication in Astronomy & Astrophysics
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2405.06350 [astro-ph.EP] (or arXiv:2405.06350v1 [astro-ph.EP] for this version)
Submission history
From: Khalid Barkaoui
[v1] Fri, 10 May 2024 09:29:39 UTC (12,730 KB)
https://arxiv.org/abs/2405.06350

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