_version_ 1866929485140459520
author Winters, Jennifer G.
Medina, Amber A.
Irwin, Jonathan M.
Charbonneau, David
Astudillo-Defru, Nicola
Horch, Elliott P.
Eastman, Jason D.
Vrijmoet, Eliot
Henry, Todd J.
Diamond-Lowe, Hannah
Winston, Elaine
Barclay, Thomas
Bonfils, Xavier
Ricker, George R.
Vanderspek, Roland
Latham, David W.
Seager, Sara
Winn, Joshua N.
Jenkins, Jon M.
Udry, St'ephane
Twicken, Joseph D.
Teske, Johanna K.
Tenenbaum, Peter
Pepe, Francesco
Murgas, Felipe
Muirhead, Philip S.
Mink, Jessica
Lovis, Christophe
Levine, Alan M.
L'epine, S'ebastien
Jao, Wei-Chun
Henze, Christopher E.
Fur'esz, G'abor
Forveille, Thierry
Figueira, Pedro
Esquerdo, Gilbert A.
Dressing, Courtney D.
D'iaz, Rodrigo F.
Delfosse, Xavier
Burke, Chris J.
Bouchy, Franois
Berlind, Perry
Almenara, Jose-Manuel
author_facet Winters, Jennifer G.
Medina, Amber A.
Irwin, Jonathan M.
Charbonneau, David
Astudillo-Defru, Nicola
Horch, Elliott P.
Eastman, Jason D.
Vrijmoet, Eliot
Henry, Todd J.
Diamond-Lowe, Hannah
Winston, Elaine
Barclay, Thomas
Bonfils, Xavier
Ricker, George R.
Vanderspek, Roland
Latham, David W.
Seager, Sara
Winn, Joshua N.
Jenkins, Jon M.
Udry, St'ephane
Twicken, Joseph D.
Teske, Johanna K.
Tenenbaum, Peter
Pepe, Francesco
Murgas, Felipe
Muirhead, Philip S.
Mink, Jessica
Lovis, Christophe
Levine, Alan M.
L'epine, S'ebastien
Jao, Wei-Chun
Henze, Christopher E.
Fur'esz, G'abor
Forveille, Thierry
Figueira, Pedro
Esquerdo, Gilbert A.
Dressing, Courtney D.
D'iaz, Rodrigo F.
Delfosse, Xavier
Burke, Chris J.
Bouchy, Franois
Berlind, Perry
Almenara, Jose-Manuel
contents We present the discovery from TESS data of LTT 1445Ab. At a distance of 6.9 parsecs, it is the second nearest transiting exoplanet system found to date, and the closest one known for which the primary is an M dwarf. The host stellar system consists of three mid-to-late M dwarfs in a hierarchical configuration, which are blended in one TESS pixel. We use data from MEarth and results from the SPOC DV report to determine that the planet transits the primary star in the system. The planet has a radius 1.38 R_Earth, an orbital period of 5.35882 days, and an equilibrium temperature of 433 K. With radial velocities from HARPS, we place a three-sigma upper mass limit of 8.4 M_Earth on the candidate. The planet provides one of the best opportunities to date for the spectroscopic study of the atmosphere of a terrestrial world. The presence of stellar companions of similar spectral type may facilitate such ground-based studies by providing a calibration source to remove telluric variations. In addition, we present a detailed characterization of the host stellar system. We use high-resolution spectroscopy and imaging to rule out the presence of any other close stellar or brown dwarf companions. Nineteen years of photometric monitoring of A and BC indicates a moderate amount of variability, in agreement with the observed low-level, short-term variability in the TESS light curve data. We derive a preliminary astrometric orbit for the BC pair that reveals an edge-on and eccentric configuration. The presence of a transiting planet in this system raises the possibility that the entire system is co-planar, which implies that the system may have formed from the early fragmentation of an individual protostellar core.
format Preprint
id arxiv_https___arxiv_org_abs_1906_10147
institution arXiv
publishDate 2019
record_format arxiv
spellingShingle Three Red Suns in the Sky: A Transiting, Terrestrial Planet in a Triple M Dwarf System at 6.9 Parsecs
Winters, Jennifer G.
Medina, Amber A.
Irwin, Jonathan M.
Charbonneau, David
Astudillo-Defru, Nicola
Horch, Elliott P.
Eastman, Jason D.
Vrijmoet, Eliot
Henry, Todd J.
Diamond-Lowe, Hannah
Winston, Elaine
Barclay, Thomas
Bonfils, Xavier
Ricker, George R.
Vanderspek, Roland
Latham, David W.
Seager, Sara
Winn, Joshua N.
Jenkins, Jon M.
Udry, St'ephane
Twicken, Joseph D.
Teske, Johanna K.
Tenenbaum, Peter
Pepe, Francesco
Murgas, Felipe
Muirhead, Philip S.
Mink, Jessica
Lovis, Christophe
Levine, Alan M.
L'epine, S'ebastien
Jao, Wei-Chun
Henze, Christopher E.
Fur'esz, G'abor
Forveille, Thierry
Figueira, Pedro
Esquerdo, Gilbert A.
Dressing, Courtney D.
D'iaz, Rodrigo F.
Delfosse, Xavier
Burke, Chris J.
Bouchy, Franois
Berlind, Perry
Almenara, Jose-Manuel
Earth and Planetary Astrophysics
We present the discovery from TESS data of LTT 1445Ab. At a distance of 6.9 parsecs, it is the second nearest transiting exoplanet system found to date, and the closest one known for which the primary is an M dwarf. The host stellar system consists of three mid-to-late M dwarfs in a hierarchical configuration, which are blended in one TESS pixel. We use data from MEarth and results from the SPOC DV report to determine that the planet transits the primary star in the system. The planet has a radius 1.38 R_Earth, an orbital period of 5.35882 days, and an equilibrium temperature of 433 K. With radial velocities from HARPS, we place a three-sigma upper mass limit of 8.4 M_Earth on the candidate. The planet provides one of the best opportunities to date for the spectroscopic study of the atmosphere of a terrestrial world. The presence of stellar companions of similar spectral type may facilitate such ground-based studies by providing a calibration source to remove telluric variations. In addition, we present a detailed characterization of the host stellar system. We use high-resolution spectroscopy and imaging to rule out the presence of any other close stellar or brown dwarf companions. Nineteen years of photometric monitoring of A and BC indicates a moderate amount of variability, in agreement with the observed low-level, short-term variability in the TESS light curve data. We derive a preliminary astrometric orbit for the BC pair that reveals an edge-on and eccentric configuration. The presence of a transiting planet in this system raises the possibility that the entire system is co-planar, which implies that the system may have formed from the early fragmentation of an individual protostellar core.
title Three Red Suns in the Sky: A Transiting, Terrestrial Planet in a Triple M Dwarf System at 6.9 Parsecs
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/1906.10147