J/A+A/696/A86 HARPS-N data of TOI-1453 (Stalport+, 2025)
TESS and HARPS-N unveil two planets transiting TOI-1453.
A super-Earth and one of the lowest mass sub-Neptunes.
Stalport M., Mortier A., Cretignier M., Egger J.A., Malavolta L.,
Latham D.W., Collins K.A., Watkins C.N., Murgas F., Buchhave L.A.,
Lopez-Morales M., Udry S., Quinn S.N., Silva A.M., Andreuzzi G.,
Baker D., Boschin W., Ciardi D.R., Damasso M., Di Fabrizio L., Dumusque X.,
Fukui A., Haywood R., Howell S.B., Jenkins J.M., Leleu A., Lewin P.,
Lillo-Box J., Martinez Fiorenzano A. F., Narita N., Pedani M., Pinamonti M.,
Poretti E., Schwarz R.P., Seager S., Sozzetti A., Ting E.B., Vanderburg A.,
Winn J.N., Ziegler C.
<Astron. Astrophys. 696, A86 (2025)>
=2025A&A...696A..86S 2025A&A...696A..86S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities
Keywords: techniques: radial velocities - planets and satellites: detection -
stars: individual: TOI-1453 : stars: individual: TIC 198390247
Abstract:
The TESS mission is searching for transiting planets over the entire
sky, including two continuous viewing zones. Data from the continuous
viewing zones span a long time baseline and offer ideal conditions for
precise planet radius estimations, enabling the community to prepare
for the PLATO mission.
We report on the validation and characterisation of two transiting
planets around TOI-1453, a K-dwarf star in the TESS northern
continuous viewing zone.
In addition to the TESS data, we used ground-based photometric,
spectroscopic, and high-resolution imaging follow-up observations to
validate the two planets. We obtained 100 HARPS-N high-resolution
spectra over two seasons and used them together with the TESS light
curve to constrain the mass, radius, and orbit of each planet.
TOI-1453 b is a super-Earth with an orbital period of Pb=4.314 days, a
radius of Rb=1.17±0.06R⊕, and a mass lower than 2.32
M⊕ (99%). TOI-1453 c is a sub-Neptune with a period of
Pc=6.589 days, radius of Rc=2.22±0.09R⊕, and mass of
Mc=2.95+0.83-0.84 M⊕. The two planets orbit TOI-1453 with
a period ratio close to 3/2, although they are not in a mean motion
resonance (MMR) state. We did not detect any transit timing variations
in our attempt to further constrain the planet masses. TOI-1453 c has
a very low bulk density and is one of the least massive sub-Neptunes
discovered to date. It is compatible with having either a water-rich
composition or a rocky core surrounded by a thick H/He atmosphere.
However, we set constraints on the water mass fraction in the envelope
according to either a water-rich or water-poor formation scenario. The
star TOI-1453 belongs to the Galactic thin disc based on Gaia
kinematics and has a sub-solar metallicity. This system is orbited by
a fainter stellar companion at a projected distance of ∼150AU,
classifying TOI-1453 b and c of S-type planets. These various
planetary and stellar characteristics make TOI-1453 a valuable system
for understanding the origin of super-Earths and sub-Neptunes.
Description:
Radial velocity (RV) measurements and stellar activity indicators of
TOI-1453. Data obtained with the HARPS-N spectrograph installed at the
TNG in Roque de los Muchachos observatory (La Palma, Canarias). The
dataset presented here and used in the paper was derived with the
YARARA post-process (Cretignier et al., 2021A&A...653A..43C 2021A&A...653A..43C), with
stellar activity component injected back.
Objects:
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RA (2000) DE Designation(s)
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17 12 53.72 +57 11 52.0 TOI-1453 = TIC 198390247
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea2.dat 112 94 HARPS-N YARARA-V1 RV and activity indicators
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d BJD Barycentric Julian Date of observation
(BJD-2400000)
13- 19 F7.4 m/s RV Relative radial velocity
22- 27 F6.4 m/s e_RV Relative radial velocity uncertainty
29- 40 F12.7 m/s FWHM FWHM
42- 50 F9.7 m/s e_FWHM FWHM uncertainty
52- 61 F10.7 [-] RHK RHK activity index
63- 71 F9.7 [-] e_RHK RHK activity index uncertainty
73- 82 F10.7 m/s Bis Bisector span of CCF
84- 92 F9.7 m/s e_Bis Bisector span uncertainty
94-102 F9.7 [-] Ha H-alpha index
104-112 F9.7 [-] e_Ha H-alpha index uncertainty
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Acknowledgements:
Manu Stalport, manu.stalport(at)uliege.be
(End) Patricia Vannier [CDS] 13-Mar-2025