Two temperate super-Earths transiting a nearby late-type M dwarf
Por:
Delrez, L., Murray, C. A., Pozuelos, F. J., Narita, N., Ducrot, E., Timmermans, M., Watanabe, N., Burgasser, A. J., Hirano, T., Rackham, V, B., Stassun, K. G., Van Grootel, V., Aganze, C., Cointepas, M., Howell, S., Kaltenegger, L., Niraula, P., Sebastian, D., Almenara, J. M., Barkaoui, K., Baycroft, T. A., Bonfils, X., Bouchy, F., Burdanov, A., Caldwell, D. A., Charbonneau, D., Ciardi, D. R., Collins, K. A., Daylan, T., Demory, B-O, Guenther, N., de Wit, J., Dransfield, G., Fajardo-Acosta, S. B., Fausnaugh, M., Fukui, A., Furlan, E., Garcia, L. J., Gnilka, C. L., Chew, Y. Gomez Maqueo, Gomez-Munoz, M. A., Harakawa, H., Heng, K., Hooton, M. J., Hori, Y., Ikoma, M., Jehin, E., Jenkins, J. M., Kagetani, T., Kawauchi, K., Kimura, T., Kodama, T., Kotani, T., Krishnamurthy, V, Kudo, T., Kunovac, V, Kusakabe, N., Latham, D. W., Littlefield, C., McCormac, J., Melis, C., Mori, M., Murgas, F., Palle, E., Pedersen, P. P., Queloz, D., Ricker, G., Sabin, L., Schanche, N., Schroffenegger, U., Seager, S., Shiao, B., Sohy, S., Standing, M. R., Tamura, M., Theissen, C. A., Thompson, S. J., Triaud, A. H. M. J., Vanderspek, R., Vievard, S., Wells, R. D., Winn, J. N., Zou, Y., Zuniga-Fernandez, S., Gillon, M.
Publicada:
8 nov 2022
Resumen:
Context. In the age of JWST, temperate terrestrial exoplanets transiting
nearby late-type M dwarfs provide unique opportunities for
characterising their atmospheres, as well as searching for biosignature
gases. In this context, the benchmark TRAPPIST-1 planetary system has
garnered the interest of a broad scientific community.
Aims. We report here the discovery and validation of two temperate
super-Earths transiting LP 890-9 (TOI-4306, SPECULOOS-2), a relatively
low-activity nearby (32 pc) M6V star. The inner planet, LP 890-9 b, was
first detected by TESS (and identified as TOI-4306.01) based on four
sectors of data. Intensive photometric monitoring of the system with the
SPECULOOS Southern Observatory then led to the discovery of a second
outer transiting planet, LP 890-9 c (also identified as SPECULOOS-2 c),
previously undetected by TESS. The orbital period of this second planet
was later confirmed by MuSCAT3 follow-up observations.
Methods. We first inferred the properties of the host star by analyzing
its Lick/Kast optical and IRTF/SpeX near-infrared spectra, as well as
its broadband spectral energy distribution, and Gaia parallax. We then
derived the properties of the two planets by modelling multi-colour
transit photometry from TESS, SPECULOOS-South, MuSCAT3, ExTrA,
TRAPPIST-South, and SAINT-EX. Archival imaging, Gemini-South/Zorro
high-resolution imaging, and Subaru/IRD radial velocities also support
our planetary interpretation.
Results. With a mass of 0.118 +/- 0.002 M-circle dot, a radius of 0.1556
+/- 0.0086 R-circle dot, and an effective temperature of 2850 +/- 75 K,
LP 890-9 is the second-coolest star found to host planets, after
TRAPPIST-1. The inner planet has an orbital period of 2.73 d, a radius
of 1.320 (+0.053)(-0.027)$1.320_{ - 0.027<^>{ +
0.053\$1.320-0.027+0.053 R-circle plus, and receives an incident
stellar flux of 4.09 +/- 0.12 S-circle plus. The outer planet has a
similar size of 1.367 (+0.055)(-0.039)$1.367_{ - 0.039<^>{ +
0.055\$1.367-0.039+0.055R(circle plus) and an orbital period of 8.46
d. With an incident stellar flux of 0.906 +/- 0.026 S-circle plus, it is
located within the conservative habitable zone, very close to its inner
limit (runaway greenhouse). Although the masses of the two planets
remain to be measured, we estimated their potential for atmospheric
characterisation via transmission spectroscopy using a mass-radius
relationship and found that, after the TRAPPIST-1 planets, LP 890-9 c is
the second-most favourable habitable-zone terrestrial planet known so
far (assuming for this comparison a similar atmosphere for all planets).
Conclusions. The discovery of this remarkable system offers another rare
opportunity to study temperate terrestrial planets around our smallest
and coolest neighbours.
Filiaciones:
Delrez, L.:
(Corresponding Author), Univ Liege, Astrobiol Res Unit, Allee 6 Aout 19C, B-4000 Liege, Belgium
(Corresponding Author), Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee 6 Aout 19C, B-4000 Liege, Belgium
Univ Liege, Astrobiol Res Unit, Allee 6 Aout 19C, B-4000 Liege, Belgium
Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee 6 Aout 19C, B-4000 Liege, Belgium
Murray, C. A.:
Cavendish Lab, JJ Thomson Ave, Cambridge CB3 0HE, England
Univ Colorado, Boulder, CO 80309 USA
Pozuelos, F. J.:
Univ Liege, Astrobiol Res Unit, Allee 6 Aout 19C, B-4000 Liege, Belgium
Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee 6 Aout 19C, B-4000 Liege, Belgium
Inst Astrofis Andalucia IAA CSIC, Glorieta Astron S-N, Granada 18008, Spain
Narita, N.:
Univ Tokyo, Komaba Inst Sci, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan
Astrobiol Ctr, 2-21-1 Osawa, Mitaka, Tokyo 2211, Japan
Inst Astrofis Canarias IAC, Tenerife 38205, Spain
Ducrot, E.:
Univ Paris, Univ Paris Saclay, CNRS, CEA,AIM, F-91191 Gif Sur Yvette, France
Timmermans, M.:
Univ Liege, Astrobiol Res Unit, Allee 6 Aout 19C, B-4000 Liege, Belgium
Watanabe, N.:
Univ Tokyo, Grad Sch Arts & Sci, Dept Multidisciplinary Sci, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan
Burgasser, A. J.:
Univ Calif San Diego, Ctr Astrophys & Space Sci, UCSD Mail Code 0424,9500 Gilman Dr, La Jolla, CA 92093 USA
Hirano, T.:
Astrobiol Ctr, 2-21-1 Osawa, Mitaka, Tokyo 2211, Japan
Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
Stassun, K. G.:
Vanderbilt Univ, Dept Phys & Astron, 6301 Stevenson Ctr Ln, Nashville, TN 37235 USA
Van Grootel, V.:
Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee 6 Aout 19C, B-4000 Liege, Belgium
Aganze, C.:
Univ Calif San Diego, Ctr Astrophys & Space Sci, UCSD Mail Code 0424,9500 Gilman Dr, La Jolla, CA 92093 USA
Cointepas, M.:
Univ Grenoble Alpes, IPAG, CNRS, F-38000 Grenoble, France
Univ Geneva, Dept Astron, Observ Geneve, Chemin Pegasi 51b, CH-1290 Versoix, Switzerland
Howell, S.:
NASA Ames Res Ctr, Moffett Field, CA 94035 USA
Kaltenegger, L.:
Cornell Univ, Dept Astron, 302 Space Sci Bldg, Ithaca, NY 14853 USA
Cornell Univ, Carl Sagan Inst, 302 Space Sci Bldg, Ithaca, NY 14853 USA
Niraula, P.:
V , MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA
Sebastian, D.:
Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England
Almenara, J. M.:
Univ Grenoble Alpes, IPAG, CNRS, F-38000 Grenoble, France
Barkaoui, K.:
Univ Liege, Astrobiol Res Unit, Allee 6 Aout 19C, B-4000 Liege, Belgium
Inst Astrofis Canarias IAC, Tenerife 38205, Spain
V , MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA
Baycroft, T. A.:
Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England
Bonfils, X.:
Univ Grenoble Alpes, IPAG, CNRS, F-38000 Grenoble, France
Bouchy, F.:
Univ Geneva, Dept Astron, Observ Geneve, Chemin Pegasi 51b, CH-1290 Versoix, Switzerland
Burdanov, A.:
V , MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA
Caldwell, D. A.:
NASA Ames Res Ctr, Moffett Field, CA 94035 USA
SETI Inst, Mountain View, CA 94043 USA
Charbonneau, D.:
Harvard & Smithsonian, Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
Ciardi, D. R.:
Caltech IPAC, Mail Code 100-22,1200 E Calif Blvd, Pasadena, CA 10022 USA
Collins, K. A.:
Harvard & Smithsonian, Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
Daylan, T.:
V , MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA
MIT, Dept Phys, Cambridge, MA 02139 USA
Princeton Univ, Dept Astrophys Sci, 4 Ivy Lane, Princeton, NJ 08544 USA
Demory, B-O:
Univ Bern, Ctr Space & Habitabil, Gesell Str 6, CH-3012 Bern, Switzerland
Guenther, N.:
European Space Res & Technol Ctr ESTEC, European Space Agcy ESA, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands
de Wit, J.:
V , MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA
Dransfield, G.:
Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England
Fajardo-Acosta, S. B.:
Caltech IPAC, Mail Code 100-22,1200 E Calif Blvd, Pasadena, CA 10022 USA
Fausnaugh, M.:
V , MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA
Fukui, A.:
Univ Tokyo, Komaba Inst Sci, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan
Inst Astrofis Canarias IAC, Tenerife 38205, Spain
Furlan, E.:
Caltech IPAC, Mail Code 100-22,1200 E Calif Blvd, Pasadena, CA 10022 USA
Garcia, L. J.:
Univ Liege, Astrobiol Res Unit, Allee 6 Aout 19C, B-4000 Liege, Belgium
Gnilka, C. L.:
NASA Ames Res Ctr, Moffett Field, CA 94035 USA
Chew, Y. Gomez Maqueo:
Univ Nacl Autonoma Mexico, Inst Astron, Ciudad De Mexico 70264, AP, Mexico
Gomez-Munoz, M. A.:
Univ Nacl Autonoma Mexico, Inst Astron, AP 106, Ensenada 22800, Baja California, Mexico
Harakawa, H.:
Subaru Telescope, 650 N Aohoku Pl, Hilo, HI 96720 USA
Heng, K.:
Univ Bern, Ctr Space & Habitabil, Gesell Str 6, CH-3012 Bern, Switzerland
Univ Warwick, Dept Phys, Gibbet Hill Rd, Coventry CV4 7AL, W Midlands, England
Hooton, M. J.:
Cavendish Lab, JJ Thomson Ave, Cambridge CB3 0HE, England
Hori, Y.:
Astrobiol Ctr, 2-21-1 Osawa, Mitaka, Tokyo 2211, Japan
Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
Ikoma, M.:
Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
Jehin, E.:
Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee 6 Aout 19C, B-4000 Liege, Belgium
Jenkins, J. M.:
NASA Ames Res Ctr, Moffett Field, CA 94035 USA
Kagetani, T.:
Univ Tokyo, Grad Sch Arts & Sci, Dept Multidisciplinary Sci, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan
Kawauchi, K.:
Inst Astrofis Canarias IAC, Tenerife 38205, Spain
Univ La Laguna ULL, Dept Astrofis, Tenerife 38206, Spain
Kimura, T.:
Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan
Kodama, T.:
Univ Tokyo, Komaba Inst Sci, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan
Kotani, T.:
Astrobiol Ctr, 2-21-1 Osawa, Mitaka, Tokyo 2211, Japan
Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
Grad Univ Adv Studies SOKENDAI, Sch Sci, Dept Astron, 2-21-1 Osawa, Mitaka, Tokyo, Japan
Krishnamurthy, V:
Astrobiol Ctr, 2-21-1 Osawa, Mitaka, Tokyo 2211, Japan
Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
Kudo, T.:
Subaru Telescope, 650 N Aohoku Pl, Hilo, HI 96720 USA
Kunovac, V:
Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England
Lowell Observ, 1400 W Mars Hill Rd, Flagstaff, AZ 86001 USA
Kusakabe, N.:
Astrobiol Ctr, 2-21-1 Osawa, Mitaka, Tokyo 2211, Japan
Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
Latham, D. W.:
Harvard & Smithsonian, Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
Littlefield, C.:
NASA Ames Res Ctr, Moffett Field, CA 94035 USA
Bay Area Environm Res Inst, Moffett Field, CA 94035 USA
McCormac, J.:
Univ Warwick, Dept Phys, Gibbet Hill Rd, Coventry CV4 7AL, W Midlands, England
Melis, C.:
Univ Calif San Diego, Ctr Astrophys & Space Sci, UCSD Mail Code 0424,9500 Gilman Dr, La Jolla, CA 92093 USA
Mori, M.:
Univ Tokyo, Grad Sch Sci, Dept Astron, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan
Murgas, F.:
Inst Astrofis Canarias IAC, Tenerife 38205, Spain
Univ La Laguna ULL, Dept Astrofis, Tenerife 38206, Spain
Palle, E.:
Inst Astrofis Canarias IAC, Tenerife 38205, Spain
Univ La Laguna ULL, Dept Astrofis, Tenerife 38206, Spain
Pedersen, P. P.:
Cavendish Lab, JJ Thomson Ave, Cambridge CB3 0HE, England
Queloz, D.:
Cavendish Lab, JJ Thomson Ave, Cambridge CB3 0HE, England
Ricker, G.:
V , MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA
MIT, Dept Phys, Cambridge, MA 02139 USA
Sabin, L.:
Univ Nacl Autonoma Mexico, Inst Astron, AP 106, Ensenada 22800, Baja California, Mexico
Schanche, N.:
Univ Bern, Ctr Space & Habitabil, Gesell Str 6, CH-3012 Bern, Switzerland
Schroffenegger, U.:
Univ Bern, Ctr Space & Habitabil, Gesell Str 6, CH-3012 Bern, Switzerland
Seager, S.:
V , MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA
V , MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA
MIT, Dept Phys, Cambridge, MA 02139 USA
MIT, Dept Aeronaut & Astronaut, 77 Massachusetts Ave, Cambridge, MA 02139 USA
Shiao, B.:
Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA
Sohy, S.:
Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee 6 Aout 19C, B-4000 Liege, Belgium
Standing, M. R.:
Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England
Tamura, M.:
Astrobiol Ctr, 2-21-1 Osawa, Mitaka, Tokyo 2211, Japan
Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
Univ Tokyo, Grad Sch Sci, Dept Astron, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan
Theissen, C. A.:
Univ Calif San Diego, Ctr Astrophys & Space Sci, UCSD Mail Code 0424,9500 Gilman Dr, La Jolla, CA 92093 USA
Thompson, S. J.:
Cavendish Lab, JJ Thomson Ave, Cambridge CB3 0HE, England
Triaud, A. H. M. J.:
Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England
Vanderspek, R.:
V , MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA
Vievard, S.:
Astrobiol Ctr, 2-21-1 Osawa, Mitaka, Tokyo 2211, Japan
Subaru Telescope, 650 N Aohoku Pl, Hilo, HI 96720 USA
Wells, R. D.:
Univ Bern, Ctr Space & Habitabil, Gesell Str 6, CH-3012 Bern, Switzerland
Winn, J. N.:
Princeton Univ, Dept Astrophys Sci, 4 Ivy Lane, Princeton, NJ 08544 USA
Zou, Y.:
Univ Tokyo, Grad Sch Arts & Sci, Dept Multidisciplinary Sci, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan
Zuniga-Fernandez, S.:
Univ Liege, Astrobiol Res Unit, Allee 6 Aout 19C, B-4000 Liege, Belgium
Gillon, M.:
Univ Liege, Astrobiol Res Unit, Allee 6 Aout 19C, B-4000 Liege, Belgium
hybrid, Green Submitted, Hybrid Gold
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