J/ApJ/946/L4 Follow-up light curves of the host star TOI-3235 (Hobson+, 2023)
TOI-3235 b: a transiting giant planet around an M4 dwarf star.
Hobson M.J., Jordan A., Bryant E.M., Brahm R., Bayliss D., Hartman J.D.,
Bakos G.A., Henning T., Almenara J.M., Barkaoui K., Benkhaldoun Z.,
Bonfils X., Bouchy F., Charbonneau D., Cointepas M., Collins K.A.,
Eastman J.D., Ghachoui M., Gillon M., Goeke R.F., Horne K., Irwin J.M.,
Jehin E., Jenkins J.M., Latham D.W., Moldovan D., Murgas F.,
Pozuelos F.J., Ricker G.R., Schwarz R.P., Seager S., Srdoc G.,
Striegel S., Timmermans M., Vanderburg A., Vanderspek R., Winn J.N.
<Astrophys. J., 946, L4 (2023)>
=2023ApJ...946L...4H 2023ApJ...946L...4H
ADC_Keywords: Stars, M-type; Photometry, ugriz; Exoplanets
Keywords: Exoplanets ; Transit photometry ; Radial velocity ; M dwarf stars
Abstract:
We present the discovery of TOI-3235 b, a short-period Jupiter
orbiting an M dwarf with a stellar mass close to the critical mass at
which stars transition from partially to fully convective. TOI-3235 b
was first identified as a candidate from TESS photometry and confirmed
with radial velocities from ESPRESSO and ground-based photometry from
HATSouth, MEarth-South, TRAPPIST-South, LCOGT, and ExTrA. We find that
the planet has a mass of 0.665±0.025MJ and a radius of
1.017±0.044RJ. It orbits close to its host star, with an orbital
period of 2.5926 days but has an equilibrium temperature of ∼604K,
well below the expected threshold for radius inflation of hot
Jupiters. The host star has a mass of 0.3939±0.0030M☉, a
radius of 0.3697±0.0018R☉, an effective temperature of 3389K,
and a J-band magnitude of 11.706±0.025. Current planet formation
models do not predict the existence of gas giants such as TOI-3235 b
around such low-mass stars. With a high transmission spectroscopy
metric, TOI-3235 b is one of the best-suited giants orbiting M dwarfs
for atmospheric characterization.
Description:
TOI-3235 was observed by the TESS primary and extended missions, in
sectors 11 (2019 April 23rd to May 20th) and 38 (2021 April 29th to
May 26th), respectively. For our analysis, we downloaded the TESS
PDCSAP light curves processed by the TESS Science Processing Operation
Center (SPOC) pipeline at NASA Ames Research Center, from the
TESS-SPOC High Level Science Product on MAST. See Section 2.1.1.
HATSouth is a network of 24 telescopes, distributed in three sites at
Las Campanas Observatory (LCO) in Chile, the site of the H.E.S.S.
gamma-ray observatory in Namibia, and Siding Spring Observatory in
Australia. HATSouth observed TOI-3235 from 2017 February 11th through
2017 May 15th from all three sites. See Section 2.1.2.
MEarth-South is an array of eight 0.4m telescopes at the Cerro Tololo
Inter-American Observatory (CTIO) in Chile. MEarth observed TOI-3235
with six telescopes on 2021 June 21st in the RG715 filter with 60s
exposure time, obtaining a full transit of TOI-3235.01.
See Section 2.1.3.
TRAPPIST-South is a 0.6m Ritchey-Chretien robotic telescope at
La Silla Observatory in Chile. A full transit of TOI-3235.01 was
observed by TRAPPIST-South on 2022 May 10th in the Sloan-z' filter
with an exposure time of 100s. See Section 2.1.4.
The Las Cumbres Observatory global telescope network (LCOGT) network
is a globally distributed network of 1m telescopes. TOI-3235 was
observed by LCOGT with the SINISTRO instrument at the South Africa
Astronomical Observatory site in the Sloan-i' band on 2021 June 10th
and at the CTIO site in the Sloan-g' band on 2022 July 1st, full
transits of TOI-3235.01 being obtained in both observations.
See Section 2.1.5.
The Exoplanets in Transits and their Atmospheres (ExTrA) facility is
composed of a near-infrared (0.85-1.55um) multiobject spectrograph fed
by three 0.6m telescopes located at La Silla observatory in Chile. We
observed five full transits of TOI-3235.01 on 2022 March 2nd (with
three telescopes) and on 2022 March 28th, 2022 April 2nd,
2022 April 23rd, and 2022 May 24th (with two telescopes). We observed
using the fibers with 8" apertures and used the low-resolution mode of
the spectrograph (R∼20) and 60s exposures for all nights.
See Section 2.1.6.
The Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic
Observations (ESPRESSO) is an ultrastable fiber-fed echelle
high-resolution spectrograph installed at the incoherent combined
Coude facility of the Very Large Telescope (VLT) in Paranal
Observatory, Chile. We observed TOI-3235 with ESPRESSO in
high-resolution mode (1 UT, R∼140000) between 2022 February 2nd and
14th, obtaining seven spectra under program ID 108.22B4.001 aka
0108.C-0123(A). See Section 2.2.
Objects:
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RA (ICRS) DE Designation(s)
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13 49 53.97 -46 03 58.4 TOI-3235 = TIC 243641947
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 13185 Light curve data for TOI-3235
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/354 : StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022)
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)
J/A+A/327/1039 : Structure and evolution of low-mass stars (Chabrier+ 1997)
J/ApJ/710/1724 : Follow-up photometry for HAT-P-11 (Bakos+, 2010)
J/A+A/546/A14 : Limb-darkening for CoRoT, Kepler, Spitzer (Claret+, 2012)
J/A+A/552/A16 : Limb-darkening for CoRoT, Kepler, Spitzer. II. (Claret+, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/AJ/145/5 : Follow-up photometry of HATS-1 (Penev+, 2013)
J/A+A/551/A80 : WASP-80 photometric and radial velocity data (Triaud+, 2013)
J/ApJ/807/45 : Habitable planets around M dwarfs (Dressing+, 2015)
J/AJ/149/166 : Photometry and spectroscopy of HATS-6 (Hartman+, 2015)
J/ApJ/831/125 : ALMA 887um obs. of ChaI star-forming region (Pascucci+, 2016)
J/ApJ/831/64 : Mass-metallicity relation for giant planets (Thorngren+, 2016)
J/A+A/618/A20 : Limb-darkening for TESS, Kepler, Corot, MOST (Claret, 2018)
J/ApJ/856/23 : BANYAN. XI. The BANYAN Σ algorithm (Gagne+, 2018)
J/AJ/157/55 : RVs and light curves for HATS-60-HATS-69 (Hartman+, 2019)
J/ApJ/871/63 : How to constrain your M dwarf. II. Nearby bin. (Mann+, 2019)
J/other/Sci/365.1441 : GJ 3512 radial velocity & light curves (Morales+, 2019)
J/AJ/159/267 : Observations & radial velocity of HATS-71b (Bakos+, 2020)
J/A+A/642/A121 : LHS1140 radial velocity data (Lillo-Box+, 2020)
J/ApJS/254/39 : Exoplanet candidates from TESS first 2yr obs (Guerrero+, 2021)
J/AJ/163/125 : LC & radial velocity of 4 giants planets (Jordan+, 2022)
J/ApJS/259/33 : Faint-star TOIs from TESS Primary Mission (Kunimoto+, 2022)
J/AJ/165/120 : g & i'-band light curve of TOI-5205 with SDSS (Kanodia+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD Barycentric Julian Date (1)
15- 22 F8.5 mag mag [-7.1/13.9] Apparent magnitude in Filt (2)
24- 30 F7.5 mag e_mag [0.0013/0.13] Uncertainty in mag
32- 39 F8.5 mag Omag [-0.11/0.2] Raw magnitude in Filter (3)
41- 42 A2 --- Filt Filter
44- 61 A18 --- Inst Instrument
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Note (1): Computed on the TDB system with correction for leap seconds.
Note (2): The out-of-transit level has been subtracted. For observations made
with the HATSouth instruments these magnitudes have been corrected for
trends using the EPD and TFA procedures applied prior to fitting the
transit model. This procedure may lead to an artificial dilution in
the transit depths when used in its plain mode, instead of the signal
reconstruction mode (Kovacs+ 2005MNRAS.356..557M 2005MNRAS.356..557M).
The blend factors for the HATSouth light curves are listed in
Table 5. For observations made with follow-up instruments (anything
other than "HATSouth" in the "Inst" column), the magnitudes have
been corrected for a quadratic trend in time, and for variations
correlated with up to three PSF shape parameters, fit simultaneously
with the transit.
Note (3): Values without correction for the quadratic trend in time,
or for trends correlated with the seeing.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 28-Feb-2025