J/A+A/698/A68 Hot Rocks Survey II. TOI-1468 b fluxes (Meier Valdes+, 2025)
Hot Rocks Survey II: The thermal emission of TOI-1468 b reveals a hot bare rock.
Meier Valdes E.A., Demory B.-O., Diamond-Lowe H., Mendonca J.M.,
August P.C., Fortune M., Allen N.H., Kitzmann D., Gressier A., Hooton M.,
Jones K.D., Buchhave L.A., Espinoza N., Fisher C.E., Gibson N.P., Heng K.,
Hoeijmakers J., Prinoth B., Rathcke A.D., Eastman J.D.
<Astron. Astrophys. 698, A68 (2025)>
=2025A&A...698A..68M 2025A&A...698A..68M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Stars, M-type ;
Photometry, infrared
Keywords: techniques: photometric - planets and satellites: atmospheres -
planets and satellites: individual: TOI-1468 b
Abstract:
Terrestrial exoplanets orbiting nearby small, cool stars known as M
dwarfs are well suited for atmospheric characterisation. Given the
strong XUV irradiation from M dwarf host stars, orbiting exoplanets
are thought to be unable to retain primordial H/He-dominated
atmospheres. However, the survivability of heavier secondary
atmospheres is currently unknown. The aim of the Hot Rocks Survey
programme is to determine if exoplanets can retain secondary
atmospheres in the presence of M dwarf hosts. Among the sample of 9
exoplanets in the programme, here we aim to determine whether
TOI-1468 b has a substantial atmosphere or is consistent with a
low-albedo bare rock. The James Webb Space Telescope provides an
opportunity to characterise the thermal emission with MIRI at 15um.
TOI-1468 b occultation was observed three times. We compare our
observations to atmospheric models including varying amounts of CO2
and H2O. The observed occultation depth for the individual visits
are 239±52ppm, 341±53ppm and 357±52ppm. A joint fit yields an
occultation depth of 311±31ppm. The thermal emission is mostly
consistent with no atmosphere and zero Bond albedo at 1.65-σ
confidence level or a blackbody at a brightness temperature of
1024±78K. A pure CO2 or H2O atmosphere with a surface pressure
above 1bar is ruled out over 3-σ. Surprisingly, TOI-1468 b
presents a surface marginally hotter than expected, hinting at an
additional source of energy on the planet. It could originate from a
temperature inversion, induction heating or be an instrumental
artifact. The results within the Hot Rocks Survey build on the legacy
of studying the atmospheres of exoplanets around M dwarfs. The outcome
of this survey will prove useful to the large-scale survey on M dwarfs
recently approved by the STScI.
Description:
We present JWST MIRI photometry at 15um containing three
observations of the eclipse of TOI-1468 b. process.dat contains the
photometric time-series after processing the raw images with the
software Eureka!, along with detrending variables. detrended.csv
contains the detrended photometric time-series. Raw data can be
obtained from the Barbara A. Mikulski Archive for Space Telescopes
(MAST) portal:
https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html
Objects:
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RA (2000) DE Designation(s)
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01 06 36.97 +19 13 33.1 TOI-1468 = TIC 243185500
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
process.dat 101 4344 JWST processed time-series with detrending
variables
detrend.dat 48 3395 JWST detrended photometric time-series
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See also:
J/A+A/666/A155 : TOI-1468 photometry and radial velocities (Chaturvedi+, 2022)
https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html : MAST archive
Byte-by-byte Description of file: process.dat
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Bytes Format Units Label Explanations
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1- 18 F18.10 d Time BJD time
20- 39 F20.12 e Flux ?=- Absolute flux
41- 57 F17.12 e e_Flux Flux uncertainty
59- 70 F12.8 pix X Centroid position X
72- 83 F12.8 pix Y Centroid position Y
85-101 F17.12 e bg Background flux
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Byte-by-byte Description of file: detrend.dat
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Bytes Format Units Label Explanations
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1- 18 F18.10 d Time BJD time
20- 33 F14.12 --- Flux Normalised detrended flux
35- 48 F14.12 --- e_Flux Normalised flux error
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Acknowledgements:
Erik Meier Valdes, erik.meiervaldes(at)physics.ox.ac.uk
References:
August et al., Paper I 2025A&A...695A.171A 2025A&A...695A.171A
(End) Patricia Vannier [CDS] 27-Mar-2025