Issue |
A&A
Volume 670, February 2023
|
|
---|---|---|
Article Number | A136 | |
Number of page(s) | 28 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202245129 | |
Published online | 20 February 2023 |
A sub-Neptune planet around TOI-1695 discovered and characterized with SPIRou and TESS
1
LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité,
5 place Jules Janssen,
92195
Meudon, France
e-mail: flavien.kiefer@obspm.fr
2
Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris,
98 bis bd Arago,
75014
Paris, France
3
Observatoire de Haute-Provence, CNRS, Université d’Aix-Marseille,
04870
Saint-Michel-l’Observatoire, France
4
LaboratOrio Nacional de Astrofísica,
Rua Estados Unidos 154,
37504-364
Itajubá – MG, Brazil
5
Université de Montréal, Département de Physique, IREX,
Montréal, QC
H3C 3J7, Canada
6
Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, IRAP/UMR 5277,
14 avenue Edouard Belin,
31400
Toulouse, France
7
CNRS, IPAG, Université Grenoble Alpes,
F-38000
Grenoble, France
8
NASA Exoplanet Science Institute, Caltech/IPAC,
Pasadena, CA
91125, USA
9
Department of Astronomy and Astrophysics, University of California,
Santa Cruz, CA
95064, USA
10
Department of Physics and Astronomy, Vanderbilt University,
Nashville, TN
37235, USA
11
Instituto de Astrofísica e Ciencias do Espaço, Universidade do Porto, CAUP,
Rua das Estrelas,
4150-762
Porto, Portugal
12
European Southern Observatory, Alonso de Cordova,
Vitacura, Santiago, Chile
13
Canada-France-Hawaii Telescope, CNRS,
96743
Kamuela, Hawaii, USA
14
Institut de Recherche sur les Exoplanètes, Département de Physique, Université de Montréal,
1375 Avenue Thérèse-Lavoie-Roux,
Montréal, QC
H2V 0B3, Canada
15
Aix-Marseille Univ., CNRS, CNES, Institut Origines, LAM,
Marseille, France
16
Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology,
Cambridge, MA
02139, USA
17
Space Telescope Science Institute,
3700 San Martin Drive,
Baltimore, MD,
21218, USA
18
Center for Astrophysics, Harvard & Smithsonian,
60 Garden St,
Cambridge, MA
02138, USA
19
MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology,
Cambridge, MA
02139, USA
20
Earth and Planetary Sciences, Massachusetts Institute of Technology,
77 Massachusetts Avenue,
Cambridge, MA
02139, USA
21
Department of Aeronautics and Astronautics, MIT,
77 Massachusetts Avenue,
Cambridge, MA
02139, USA
22
NASA Ames Research Center,
Moffett Field, CA
94035, USA
23
SETI Institute,
Mountain View, CA
94043, USA
24
Department of Astrophysical Sciences,
Peyton Hall, 4 Ivy Lane,
Princeton, NJ
08544, USA
25
Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP,
Rua das Estrelas,
4150-762
Porto, Portugal
26
LATMOS/IPSL, UVSQ Université Paris-Saclay, Sorbonne Université, CNRS,
78280
Guyancourt, France
27
Institute of Astronomy and Astrophysics, Academia Sinica,
Taipei
10617, Taiwan
28
Department of Earth Sciences, University of Hawaii at Manoa,
Honolulu, Hawaii
96822 USA
29
Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Lorând Research Network (ELKH),
Konkoly- Thege Miklós út 15-17,
1121
Budapest, Hungary
30
CSFK, MTA Centre of Excellence, Budapest,
Konkoly Thege Miklós út 15-17,
1121,
Hungary
31
Max-Planck-Institute for Astronomy,
Königstuhl 17,
69117
Heidelberg, Germany
32
ELTE Eötvös Loránd University, Institute of Physics,
Pázmány Péter sétány 1/A,
1117
Budapest, Hungary
33
Universidade Federal do Rio Grande do Norte (UFRN),
59078-970,
Natal, RN, Brazil
34
Center for Astrophysics, Harvard & Smithsonian,
60 Garden Street,
Cambridge, MA
02138, USA
Received:
3
October
2022
Accepted:
8
November
2022
TOI-1695 is a V-mag = 13 M-dwarf star from the northern hemisphere at 45 pc from the Sun, around which a 3.134-day periodic transit signal from a super-Earth candidate was identified in TESS photometry. With a transit depth of 1.3 mmag, the radius of candidate TOI-1695.01 was estimated by the TESS pipeline to be 1.82 R⊕ with an equilibrium temperature of ~620 K. We successfully detected a reflex motion of the star and establish that it is due to a planetary companion at an orbital period consistent with the photometric transit period, thanks to a year-long radial-velocity monitoring of TOI-1695 by the SPIRou infrared spectropolarimeter. We used and compared different methods to reduce and analyze those data. We report a 5.5σ detection of the planetary signal, giving a mass of 5.5±1.0 M⊕ and a radius of 2.03±0.18 R⊕. We derive a mean equilibrium planet temperature of 590±90 K. The mean density of this small planet of 3.6±1.1 g cm−3 is similar (1.7σ lower) than that of the Earth. It leads to a nonnegligible fraction of volatiles in its atmosphere with fH,He = 0.28−0.23+0.46% or fwater = 23±12%. TOI-1695 b is a new sub-Neptune planet at the border of the M-dwarf radius valley that can help test formation scenarios for super-Earth and sub-Neptune-like planets.
Key words: planets and satellites: detection / planets and satellites: fundamental parameters / planets and satellites: individual: TOI-1695 b / techniques: photometric / techniques: radial velocities
© The Authors 2023
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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