J/MNRAS/533/1 RV and Photometric data of TOI-757 b (Alqasim+, 2024)
TOI-757 b: an eccentric transiting mini-Neptune on a 17.5-d orbit.
Alqasim A., Grieves N., Rosario N.M., Gandolfi D., Livingston J.H.,
Sousa S., Collins K.A., Teske J.K., Fridlund M., Egger J.A., Cabrera J.,
Hellier C., Lanza A.F., Van Eylen V., Bouchy F., Oelkers R.J., Srdoc G.,
Shectman S., Guenther M., Goffo E., Wilson T., Serrano L.M., Brandeker A.,
Wang S.X., Heitzmann A., Bonfanti A., Fossati L., Alibert Y., Delrez L.,
Sefako R., Barros S., Collins K.I., Demangeon O.D.S., Albrecht S.H.,
Alonso R., Asquier J., Barczy T., Barrado D., Baumjohann W., Beck T.,
Benz W., Billot N., Borsato L., Broeg C., Bryant E.M., Butler R.P.,
Cochran W.D., Collier Cameron A., Correia A.C.M., Crane J.D.,
Csizmadia Sz., Cubillos P.E., Davies M.B., Daylan T., Deleuil M., Deline A.,
Demory B.-O., Derekas A., Edwards B., Ehrenreich D., Erikson A., Essack Z.,
Fortier A., Gazeas K., Gillon M., Gudel M., Hasiba J., Hatzes A.P.,
Helling C., Hirano T., Howell S.B., Hoyer S., Isaak K.G., Jenkins J.M.,
Kanodia S., Kiss L.L., Korth J., Lam K.W.F., Laskar J.,
Lecavelier des Etangs A., Lendl M., Lund M.B., Luque R., Mann A.W.,
Magrin D., Maxted P.F.L., Mordasini C., Narita N., Nascimbeni V., Nowak G.,
Olofsson G., Osborn H.P., Osborne H.L.M., Osip D., Ottensamer R., Pagano I.,
Palle E., Peter G., Piotto G., Pollacco D., Queloz D., Ragazzoni R.,
Rando N., Rauer H., Redfield S., Ribas I., Rice M., Ricker G.R., Rieder M.,
Salmon S., Santos N.C., Scandariato G., Seager S., Segransan D., Shporer A.,
Simon A.E., Smith A.M.S., Stalport M., Szabo Gy.M., Thompson I.,
Twicken J.D., Udry S., Vanderspek R., Van Grootel V., Venturini J.,
Villaver E., Villasenor J., Viotto V., Walter I., Walton N.A., Winn J.N.,
Yee S.W.
<Mon. Not. R. Astron. Soc. 533, 1-26 (2024)>
=2024MNRAS.533....1A 2024MNRAS.533....1A (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, K-type ; Exoplanets ;
Photometry ; Optical ; Radial velocities
Keywords: techniques: photometric - techniques: radial velocities -
planets and satellites: composition -
planets and satellites: interiors -
stars: individual: TOI-757 (TIC 130924120)
Abstract:
We report the spectroscopic confirmation and fundamental properties of
TOI-757 b, a mini-Neptune on a 17.5-day orbit transiting a bright star
(V=9.7mag) discovered by the TESS mission. We acquired high-precision
radial velocity measurements with the HARPS, ESPRESSO, and PFS
spectrographs to confirm the planet detection and determine its mass.
We also acquired space-borne transit photometry with the CHEOPS space
telescope to place stronger constraints on the planet radius,
supported with ground-based LCOGT photometry. WASP and KELT photometry
were used to help constrain the stellar rotation period. We also
determined the fundamental parameters of the host star. We find that
TOI-757 b has a radius of Rp=2.5±0.1R⊕ and a mass of
Mp=10.5+2.2-2.1M⊕, implying a bulk density of
ρp=3.6±0.8g/cm3. Our internal composition modeling was
unable to constrain the composition of TOI-757 b, highlighting the
importance of atmospheric observations for the system. We also find
the planet to be highly eccentric with e=0.39+0.08-0.07, making it
one of the very few highly eccentric planets among precisely
characterized mini-Neptunes. Based on comparisons to other similar
eccentric systems, we find a likely scenario for TOI-757 b's formation
to be high eccentricity migration due to a distant outer companion. We
additionally propose the possibility of a more intrinsic explanation
for the high eccentricity due to star-star interactions during the
earlier epoch of the Galactic disk formation, given the low
metallicity and older age of TOI-757.
Description:
We present the confirmation and the planet properties of TOI-757 b, a
transiting mini-Neptune that was discovered by the TESS mission.
Through the photometric and RV analyses, we find that TOI-757 b has a
radius of Rp=2.5±0.1R⊕ and a mass of
Mp=10.5+2.2-2.1M⊕, giving us an implied density of
ρp=3.6±0.8g/cm3. We find the planet to be highly eccentric
with e=0.39+0.08-0.07, making it one of the very few highly
eccentric mini-Neptunes among all precisely known exoplanets from the
mini-Neptune population.
The radial velocities and photometry used in the paper are included here.
Objects:
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RA (2000) DE Designation(s)
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12 31 58.70 -35 33 17.6 TOI-757 = TIC 130924120
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
rv.dat 259 73 HARPS, ESPRESSO and PFS radial velocity
observations of TOI-757
photom.dat 72 49719 TESS, CHEOPS and LCOGT photometric observations
of TOI-757
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Byte-by-byte Description of file: rv.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.13 d Time TESS Barycentric Julian Date (BTJD)
(BJD - 2457000)
20- 40 F21.18 m/s RV Radial velocity
42- 59 F18.16 m/s e_RV Radial velocity error
61- 68 A8 --- Tel Instrument used: HARPS, ESPRESSO or PFS
70 I1 --- InstId [0/2] Instrument identifier (1)
72- 90 F19.15 m/s CCFBIS ?=- CCF Bisector velocity span
92-109 F18.16 m/s e_CCFBIS ?=- CCF Bisector velocity span
error = 2*e_RV
111-128 F18.13 m/s CCFFWHM ?=- CCF Full Width at Half Maximum
130-147 F18.16 m/s e_CCFFWHM ?=- CCF Full Width at Half Maximum
error = 2*e_RV
149-167 F19.17 --- Sindex S-index (Mt. Wilson)
169-188 F20.18 --- e_Sindex S-index error
190-207 F18.16 --- HalphaIndex ?=- H-alpha index
209-216 A8 --- e_HalphaIndex ?=- H-alpha index error
218-234 F17.14 --- logRHK ?=- log (R'/HK) activity index
236-252 F17.15 --- e_logRHK ?=- log (R'/HK) activity index error
254-259 F6.1 s ExpTime Exposure time
--------------------------------------------------------------------------------
Note (1): Instrument identifiers are defined as below:
0 = HARPS
1 = ESPRESSO
2 = PFS
--------------------------------------------------------------------------------
Byte-by-byte Description of file: photom.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.13 d Time TESS Barycentric Julian Date (BTJD)
(BJD-2457000)
20- 43 E24.16 10-3 Flux De-trended relative flux (in ppt)
45- 63 F19.17 10-3 e_Flux Flux error (in ppt)
65- 70 A6 --- Tel Telescope used
(TESS, CHEOPS, LCO-Y, or LCO-Zs) (1)
72 I1 --- TransitId Transit ID ordered by date (2)
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Note (1): We treat LCOGT data taken with different filters separately, as
defined below:
LCO-Y = LCOGT Y-filter
LCO-Zs = LCOGT z-short filter
Note (2): The transit IDs are defined as below:
1 = Transit 1 (TESS)
2 = Transit 2 (TESS)
3 = Transit 3 (LCO-Y)
4 = Transit 4 (LCO-Zs)
5 = Transit 5 (LCO-Zs)
6 = Transit 6 (CHEOPS)
7 = Transit 7 (TESS)
8 = Transit 8 (CHEOPS)
9 = Transit 9 (TESS)
--------------------------------------------------------------------------------
Acknowledgements:
Ahlam Alqasim, ahlam.alqasim.17(at)ucl.ac.uk
(End) Patricia Vannier [CDS] 01-Aug-2024