GJ 806 (TOI-4481): A bright nearby multi-planetary system with a transiting hot low-density super-Earth
Author
Palle, E.Orell-Miquel, J.
Brady, M.
Bean, J.
Hatzes, A.P.
Morello, G.
Morales, J.C.
Murgas, F.
Molaverdikhani, K.
Parviainen, H.
Sanz-Forcada, J.
Béjar, V.J.S.
Caballero, J.A.
Sreenivas, K.R.
Schlecker, M.
Ribas, I.
Perdelwitz, V.
Tal-Or, L.
Pérez-Torres, M.
Luque, R.
Dreizler, S.
Fuhrmeister, B.
Aceituno, F.
Amado, P.J.
Anglada-Escudé, G.
Caldwell, D.A.
Charbonneau, D.
Cifuentes, C.
de Leon, J.P.
Collins, K.A.
Dufoer, S.
Espinoza, N.
Essack, Z.
Fukui, A.
Chew, Y.G.M.
Gómez-Muñoz, M.A.
Henning, T.
Herrero, E.
Jeffers, S.V.
Jenkins, J.
Kaminski, A.
Kasper, J.
Kunimoto, M.
Latham, D.
Lillo-Box, J.
López-González, M.J.
Montes, D.
Mori, M.
Narita, N.
Quirrenbach, A.
Pedraz, S.
Reiners, A.
Rodríguez, E.
Rodríguez-López, C.
Sabin, L.
Schanche, N.
Schwarz, R.-P.
Schweitzer, A.
Seifahrt, A.
Stefansson, G.
Sturmer, J.
Trifonov, T.
Vanaverbeke, S.
Wells, R.D.
Zapatero-Osorio, M.R.
Zechmeister, M.
Affiliation
Department of Astronomy/Steward Observatory, The University of ArizonaIssue Date
2023-10-09Keywords
Planetary systemsPlanets and satellites: atmospheres
Planets and satellites: detection
Planets and satellites: fundamental parameters
Planets and satellites: terrestrial planets
Metadata
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EDP SciencesCitation
GJ 806 (TOI-4481): A bright nearby multi-planetary system with a transiting hot low-density super-Earth E. Palle, J. Orell-Miquel, M. Brady, J. Bean, A. P. Hatzes, G. Morello, J. C. Morales, F. Murgas, K. Molaverdikhani, H. Parviainen, J. Sanz-Forcada, V. J. S. Béjar, J. A. Caballero, K. R. Sreenivas, M. Schlecker, I. Ribas, V. Perdelwitz, L. Tal-Or, M. Pérez-Torres, R. Luque, S. Dreizler, B. Fuhrmeister, F. Aceituno, P. J. Amado, G. Anglada-Escudé, D. A. Caldwell, D. Charbonneau, C. Cifuentes, J. P. de Leon, K. A. Collins, S. Dufoer, N. Espinoza, Z. Essack, A. Fukui, Y. Gómez Maqueo Chew, M. A. Gómez-Muñoz, Th. Henning, E. Herrero, S.V. Jeffers, J. Jenkins, A. Kaminski, J. Kasper, M. Kunimoto, D. Latham, J. Lillo-Box, M. J. López-González, D. Montes, M. Mori, N. Narita, A. Quirrenbach, S. Pedraz, A. Reiners, E. Rodríguez, C. Rodríguez-López, L. Sabin, N. Schanche, R.-P. Schwarz, A. Schweitzer, A. Seifahrt, G. Stefansson, J. Sturmer, T. Trifonov, S. Vanaverbeke, R. D. Wells, M. R. Zapatero-Osorio and M. Zechmeister A&A, 678 (2023) A80 DOI: https://doi.org/10.1051/0004-6361/202244261Journal
Astronomy and AstrophysicsRights
© The Authors 2023. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
One of the main scientific goals of the TESS mission is the discovery of transiting small planets around the closest and brightest stars in the sky. Here, using data from the CARMENES, MAROON-X, and HIRES spectrographs together with TESS, we report the discovery and mass determination of aplanetary system around the M1.5 V star GJ 806 (TOI-4481). GJ 806 is a bright (V -10.8mag, J - 7.3 mag) and nearby (d = 12 pc) M dwarf that hosts at least two planets. The innermost planet, GJ 806 b, is transiting and has an ultra-short orbital period of 0.93 d, a radius of 1.331 ± 0.023 R⊙, a mass of 1.90 ± 0.17 M⊙, a mean density of 4.40 ± 0.45 g cm-3, and an equilibrium temperature of 940 ± 10 K. We detect a second, non-transiting, super-Earth planet in the system, GJ 806 c, with an orbital period of 6.6 d, a minimum mass of 5.80 ± 0.30 M⊙, and an equilibrium temperature of 490 ± 5 K. The radial velocity data also shows evidence for a third periodicity at 13.6 d, although the current dataset does not provide sufficient evidence to unambiguously distinguish between a third super-Earth mass (M sin i = 8.50 ± 0.45 M⊙) planet or stellar activity. Additionally, we report one transit observation of GJ 806 b taken with CARMENES in search of a possible extended atmosphere of H or He, but we can only place upper limits to its existence. This is not surprising as our evolutionary models support the idea that any possible primordial H/He atmosphere that GJ 806 b might have had would be long lost. However, the bulk density of GJ 806 b makes it likely that the planet hosts some type of volatile atmosphere. With transmission spectroscopy metrics (TSM) of 44 and emission spectroscopy metrics (ESM) of 24, GJ 806 b is to date the third-ranked terrestrial planet around an M dwarf suitable for transmission spectroscopy studies using JWST, and the most promising terrestrial planet for emission spectroscopy studies. GJ 806b is also an excellent target for the detection of radio emission via star-planet interactions. © 2023 EDP Sciences. All rights reserved.Note
Open access journalISSN
0004-6361Version
Final Published Versionae974a485f413a2113503eed53cd6c53
10.1051/0004-6361/202244261
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Except where otherwise noted, this item's license is described as © The Authors 2023. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License.