Teegarden's Star revisited: A nearby planetary system with at least three planets

S. Dreizler; R. Luque; I. Ribas; V. Koseleva; H. L. Ruh; E. Nagel; F. J. Pozuelos; M. Zechmeister; A. Reiners; J. A. Caballero; P. J. Amado; V. J. S. Béjar; J. L. Bean; M. Brady; C. Cifuentes; M. Gillon; A. P. Hatzes; Th. Henning; D. Kasper; D. Montes; J. C. Morales; C. A. Murray; E. Pallé; A. Quirrenbach; A. Seifahrt; A. Schweitzer; J. Stürmer; G. Stefánsson; J. I. Vico Linares

arXiv · 2402.00923

Teegarden's Star revisited: A nearby planetary system with at least three planets

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Abstract

The two known planets in the planetary system of Teegarden's Star are among the most Earth-like exoplanets currently known. Revisiting this nearby planetary system with two planets in the habitable zone aims at a more complete census of planets around very low-mass stars. A significant number of new radial velocity measurements from CARMENES, ESPRESSO, MAROON-X, and HPF, as well as photometry from TESS motivated a deeper search for additional planets. We confirm and refine the orbital parameters of the two know planets Teegarden's Star b and c. We also report the detection of a third planet d with an orbital period of 26.13+-0.04 d and a minimum mass of 0.82+-0.17 M_Earth. A signal at 96 d is attributed to the stellar rotation period. The interpretation of a signal at 172 d remains open. The TESS data exclude transiting short-period planets down to about half an Earth radius. We compare the planetary system architecture of very low-mass stars. In the currently known configuration, the planetary system of Teegarden's star is dynamically quite different from that of TRAPPIST-1, which is more compact, but dynamically similar to others such as GJ 1002.

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S. Dreizler, R. Luque, I. Ribas, V. Koseleva, H. L. Ruh, E. Nagel, F. J. Pozuelos, M. Zechmeister, A. Reiners, J. A. Caballero, P. J. Amado, V. J. S. Béjar, J. L. Bean, M. Brady, C. Cifuentes, M. Gillon, A. P. Hatzes, Th. Henning, D. Kasper, D. Montes, J. C. Morales, C. A. Murray, E. Pallé, A. Quirrenbach, A. Seifahrt, A. Schweitzer, J. Stürmer, G. Stefánsson, J. I. Vico Linares. 2024-02-01. Teegarden's Star revisited: A nearby planetary system with at least three planets. https://arxiv.org/abs/2402.00923

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