J/A+A/682/A66 TOI-732 TESS and CHEOPS detrended light curves (Bonfanti+, 2024)
Characterising TOI-732 b and c:
New insights on the M-dwarf radius and density valley.
Bonfanti A., Brady M., Wilson T.G., Venturini J., Egger J.A., Brandeker A.,
Sousa S.G., Lendl M., Simon A.E., Queloz D., Olofsson G., Adibekyan V.,
Alibert Y., Fossati L., Hooton M.J., Kubyshkina D., Luque R., Murgas F.,
Mustill A.J., Santos N.C., Van Grootel V., Alonso R., Asquier J., Bandy T.,
Barczy T., Barrado Navascues D., Barros S.C.C., Baumjohann W., Bean J.,
Beck M., Beck T., Benz W., Bergomi M., Billot N., Borsato L., Broeg C.,
Collier Cameron A., Csizmadia Sz., Cubillos P.E., Davies M.B., Deleuil M.,
Deline A., Delrez L., Demangeon O.D.S., Demory B.-O., Ehrenreich D.,
Erikson A., Fortier A., Fridlund M., Gandolfi D., Gillon M., Guedel M.,
Guenther M.N., Heitzmann A., Helling C., Hoyer S., Isaak K.G., Kasper D.,
Kiss L.L., Lam K.W.F., Laskar J., Lecavelier des Etangs A., Magrin D.,
Maxted P.F.L., Mordasini C., Nascimbeni V., Ottensamer R., Pagano I.,
Palle E., Peter G., Piotto G., Pollacco D., Ragazzoni R., Rando N.,
Rauer H., Ribas I., Scandariato G., Segransan D., Seifahrt A.,
Smith A.M.S., Stalport M., Stefansson G., Steinberger M., Stuermer J.,
Szabo Gy.M., Thomas N., Udry S., Villaver E., Walton N.A., Westerdorff K.,
Zingales T.
<Astron. Astrophys. 682, A66 (2024)>
=2024A&A...682A..66B 2024A&A...682A..66B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ; Optical
Keywords: techniques: photometric - techniques: radial velocities -
planets and satellites: fundamental parameters -
stars: fundamental parameters
Abstract:
TOI-732 is an M dwarf hosting two transiting planets, which are
located on the two opposite sides of the radius valley. Inferring a
reliable demographics for these kind of systems is key to understand
their formation and evolution mechanisms.
By doubling the number of available space-based observations and
increasing the number of radial velocity (RV) measurements, we aim at
refining the parameters of TOI-732 b and c. We also aim at using the
results to study the slope of both the radius valley and the density
valley for a well characterised sample of M dwarf exoplanets.
We performed a global MCMC analysis by jointly modelling ground-based
light curves, CHEOPS and TESS observations, along with RV time series
both taken from the literature and obtained with the MAROON-X
spectrograph. The slopes of the M dwarf valleys were quantified via a
Support Vector Machine (SVM) procedure.
TOI-732 b is an ultra short period planet
(P=0.76837931-0.00000042+0.00000039d) with a radius
Rb=1.325-0.058+0.057R⊕, a mass
Mb=2.46±0.19M⊕, and thus a mean density
rhob=5.8-0.8+1.0g/cm3, while the outer planet at
P=12.252284±0.000013d has Rc=2.39-0.11+0.10R⊕,
Mc=8.04-0.48+0.50M⊕, and thus
rhoc=3.24-0.43+0.55g/cm3. Even with respect to the most
recently reported values, this work yields to smaller uncertainties on
the transit depths and on the RV semi-amplitudes up to a factor of
∼1.6 and ∼2.4 for TOI-732 b and c, respectively. Both our interior
structure calculations and the location of the planets in the
Mass-Radius diagram leads us to classify TOI-732 b as a super-Earth
and TOI-732 c as a mini-Neptune. Following the SVM approach, we
quantified Rslope=-0.065-0.013+0.024, which is flatter than for
Sun-like stars. In line with former analyses, we noted a more filled
radius valley for M-planets and we further quantified the density
valley slope as Rhoslope=-0.02-0.04+0.12.
Compared to FGK stars, the weaker dependence of the position of the
radius valley with orbital period might indicate a heavier influence
of formation relative to evolution mechanisms in shaping the radius
valley around M-dwarfs.
Description:
TOI-732 detrended CHEOPS and TESS light curves.
The Characterising Exoplanet Satellite (CHEOPS) collected 25 light
curves of TOI-732 from January 8 to April 10, 2022.
The Transiting Exoplanet Survey Satellite (TESS) observed the system
in cycle 1 (Sector 8; from 28 February to 26 March 2019) in cycle 3
(Sector 35; from 9 February to 7 March 2021), and in cycle 5 (Sector
62; from 12 February to 10 March 2023).
Objects:
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RA (2000) DE Designation(s)
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10 18 35.13 -11 43 00.2 TOI-732 = ** LDS 3977A
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 33 106 List of TESS and CHEOPS detrended light curve
files
lc/* . 106 Individual light curves
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- FileName Name of the table with light curve data
in subdirectory lc
11- 33 A23 --- Title Title of the table
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Byte-by-byte Description of file: lc/*
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Bytes Format Units Label Explanations
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1- 14 F14.6 d Time Observation time (BJD)
16- 23 F8.6 --- Flux Normalised detrended flux
25- 32 F8.6 --- e_Flux Flux error
34- 42 F9.6 --- Res Residuals wrt transit model
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Acknowledgements:
Andrea Bonfanti, andrea.bonfanti(at)oeaw.ac.at
(End) Andrea Bonfanti [OeAW, Austria], Patricia Vannier [CDS] 27-Nov-2023