The HD 93963 A transiting system: A 1.04d super-Earth and a 3.65 d sub-Neptune discovered by TESS and CHEOPS
Journal article, 2022
We present the discovery of two small planets transiting HD 93963A (TOI-1797), a GOV star (M-* = 1.109 +/- 0.043M(circle dot), R-* = 1.043 +/- 0.009 R-circle dot) in a visual binary system. We combined TESS and CHEOPS space-borne photometry with MuSCAT 2 ground-based photometry, 'Alopeke and PHARO high-resolution imaging, TRES and FIES reconnaissance spectroscopy, and SOPHIE radial velocity measurements. We validated and spectroscopically confirmed the outer transiting planet HD 93963 A c, a sub-Neptune with an orbital period of P-c approximate to 3.65 d that was reported to be a TESS object of interest (TOI) shortly after the release of Sector 22 data. HD 93963 A c has amass of M-c = 19.2 +/- 4.1 M-circle plus and a radius of R-c = 3.228 +/- 0.059 R-circle plus, implying a mean density of rho(c) = 3.1 +/- 0.7 g cm(-3). The inner object, HD 93963 A b, is a validated 1.04 d ultra-short period (USP) transiting super-Earth that we discovered in the TESS light curve and that was not listed as a TOI, owing to the low significance of its signal (TESS signal-to-noise ratio approximate to 6.7, TESS + CHEOPS combined transit depth D-b = 141.5(-8.3)(+8.5) ppm). We intensively monitored the star with CHEOPS by performing nine transit observations to confirm the presence of the inner planet and validate the system. HD 93963 A b is the first small (R-b = 1.35 +/- 0.042 R-circle plus) USP planet discovered and validated by TESS and CHEOPS. Unlike planet c, HD 93963 Ab is not significantly detected in our radial velocities (M-b = 7.8 +/- 3.2 M-circle plus). The two planets are on either side of the radius valley, implying that they could have undergone completely different evolution processes. We also discovered a linear trend in our Doppler measurements, suggesting the possible presence of a long-period outer planet. With a V-band magnitude of 9.2, HD 93963 A is among the brightest stars known to host a USP planet, making it one of the most favourable targets for precise mass measurement via Doppler spectroscopy and an important laboratory to test formation, evolution, and migration models of planetary systems hosting ultra-short period planets.
instrumentation: spectrographs
planets and satellites: detection
planets and satellites: fundamental parameters
instrumentation: photometers
methods: data analysis
Author
L. M. Serrano
University of Turin
D. Gandolfi
University of Turin
S. Hoyer
Aix Marseille University
A. Brandeker
Stockholm University
M. J. Hooton
University of Bern
S. Sousa
University of Porto
F. Murgas
University of La Laguna
Instituto de Astrofísica de Canarias
D. R. Ciardi
California Institute of Technology (Caltech)
S. B. Howell
NASA Ames Research Center
W. Benz
University of Bern
N. Billot
University of Geneva
H-G Floren
Stockholm University
A. Bekkelien
University of Geneva
A. Bonfanti
Austrian Academy of Sciences
A. Krenn
Austrian Academy of Sciences
Alexander James Mustill
Lund University
T. G. Wilson
University of St Andrews
H. Osborn
Massachusetts Institute of Technology (MIT)
University of Bern
H. Parviainen
Instituto de Astrofísica de Canarias
University of La Laguna
N. Heidari
Aix Marseille University
Université Nice Sophia Antipolis (UNS)
Shahid Beheshti University
E. Palle
University of La Laguna
Instituto de Astrofísica de Canarias
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
V Adibekyan
University of Porto
L. Fossati
Austrian Academy of Sciences
M. Deleuil
Aix Marseille University
E. Knudstrup
Aarhus University
Nordic Optical Telescope
K. A. Collins
Harvard-Smithsonian Center for Astrophysics
K. W. F. Lam
German Aerospace Center (DLR)
S. Grziwa
University of Cologne
S. Salmon
University of Geneva
S. H. Albrecht
Aarhus University
Y. Alibert
University of Bern
R. Alonso
Instituto de Astrofísica de Canarias
University of La Laguna
G. Anglada-Escude
Institute of Space Studies of Catalonia (IEEC)
Spanish National Research Council (CSIC)
T. Barczy
Admatis
D. Barrado y Navascues
Spanish Astrobiology Center (INTA-CSIC)
S. C. C. Barros
University of Porto
W. Baumjohann
Austrian Academy of Sciences
M. Beck
University of Geneva
T. Beck
University of Bern
A. Bieryla
Harvard-Smithsonian Center for Astrophysics
X. Bonfils
Grenoble Alpes University
P. T. Boyd
NASA Goddard Space Flight Center
C. Broeg
University of Bern
J. Cabrera
German Aerospace Center (DLR)
S. Charnoz
Paris Descartes University
B. Chazelas
University of Geneva
J. L. Christiansen
California Institute of Technology (Caltech)
A. Collier Cameron
University of St Andrews
P. Cortes-Zuleta
Aix Marseille University
Sz Csizmadia
German Aerospace Center (DLR)
M. B. Davies
Lund University
A. Deline
University of Geneva
L. Delrez
University of Geneva
University of Liège
O. D. S. Demangeon
University of Porto
B-O Demory
University of Bern
A. Dunlavey
California Institute of Technology (Caltech)
University of California at Santa Cruz
D. Ehrenreich
University of Geneva
A. Erikson
German Aerospace Center (DLR)
A. Fortier
University of Bern
A. Fukui
Instituto de Astrofísica de Canarias
University of Tokyo
Z. Garai
Eötvös Loránd University (ELTE)
Slovak Academy of Sciences
M. Gillon
University of Liège
M. Gudel
University of Vienna
G. Hebrard
Pierre and Marie Curie University (UPMC)
Aix Marseille University
K. Heng
University of Bern
The University of Warwick
C. X. Huang
Massachusetts Institute of Technology (MIT)
K. G. Isaak
European Space Research and Technology Centre (ESA ESTEC)
J. M. Jenkins
NASA Ames Research Center
L. L. Kiss
Hungarian Academy of Sciences
J. Laskar
Sorbonne University
D. W. Latham
Harvard-Smithsonian Center for Astrophysics
A. Lecavelier des Etangs
Pierre and Marie Curie University (UPMC)
M. Lendl
University of Geneva
A. M. Levine
Massachusetts Institute of Technology (MIT)
C. Lovis
University of Geneva
M. B. Lund
California Institute of Technology (Caltech)
D. Magrin
Istituto nazionale di astrofisica (INAF)
P. F. L. Maxted
Keele University
N. Narita
Instituto de Astrofísica de Canarias
University of Tokyo
Astrobiology Center, Japan
V Nascimbeni
Istituto nazionale di astrofisica (INAF)
G. Olofsson
Stockholm University
R. Ottensamer
University of Vienna
I Pagano
Istituto nazionale di astrofisica (INAF)
Pessanha
Citizen Scientist
G. Peter
German Aerospace Center (DLR)
G. Piotto
University of Padua
Istituto nazionale di astrofisica (INAF)
D. Pollacco
The University of Warwick
D. Queloz
Swiss Federal Institute of Technology in Zürich (ETH)
University of Cambridge
R. Ragazzoni
Istituto nazionale di astrofisica (INAF)
University of Padua
N. Rando
European Space Agency (ESA)
F. Ratti
European Space Agency (ESA)
H. Rauer
German Aerospace Center (DLR)
Technische Universität Berlin
Freie Universität Berlin
I Ribas
Institute of Space Studies of Catalonia (IEEC)
Spanish National Research Council (CSIC)
G. Ricker
Massachusetts Institute of Technology (MIT)
P. Rowden
Royal Astronomical Society
N. C. Santos
University of Porto
G. Scandariato
Istituto nazionale di astrofisica (INAF)
S. Seager
Massachusetts Institute of Technology (MIT)
D. Segransan
University of Geneva
A. E. Simon
University of Bern
A. M. S. Smith
German Aerospace Center (DLR)
M. Steller
Austrian Academy of Sciences
Gy M. Szabo
Eötvös Loránd University (ELTE)
N. Thomas
University of Bern
J. D. Twicken
NASA Ames Research Center
S. Udry
University of Geneva
B. Ulmer
German Aerospace Center (DLR)
V. Van Grootel
University of Liège
R. Vanderspek
Massachusetts Institute of Technology (MIT)
V. Viotto
Istituto nazionale di astrofisica (INAF)
N. Walton
University of Cambridge
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 667 A1Exoplanet diversity with satellite studies
Swedish National Space Board (174/18), 2019-02-04 -- 2023-08-01.
Subject Categories
Medical Laboratory and Measurements Technologies
Astronomy, Astrophysics and Cosmology
Signal Processing
DOI
10.1051/0004-6361/202243093