J/AJ/167/199 WIRC light curves of TOI-1420b (Vissapragada+, 2024)
Helium in the Extended Atmosphere of the Warm Superpuff TOI-1420b.
Vissapragada S., Greklek-McKeon M., Linssen D., MacLeod M.,
Thorngren D.P., Gao P., Knutson H.A., Latham D.W., Lopez-Morales M.,
Oklopcic A., Gonzalez J.P., Saidel M., Tumborang A., Yoshida S.
<Astron. J., 167, 199 (2024)>
=2024AJ....167..199V 2024AJ....167..199V
ADC_Keywords: Exoplanets; Spectra, infrared
Keywords: Exoplanet astronomy ; Exoplanet atmospheres ; Exoplanet
atmospheric evolution
Abstract:
Superpuffs are planets with exceptionally low densities
(ρ≲0.1g/cm3) and core masses (Mc≲5M⊕). Many lower-mass
(Mp≲10M⊕) superpuffs are expected to be unstable to
catastrophic mass loss via photoevaporation and/or boil-off, whereas
the larger gravitational potentials of higher-mass (Mp≳10M⊕)
superpuffs should make them more stable to these processes. We test
this expectation by studying atmospheric loss in the warm, higher-mass
superpuff TOI-1420b (M=25.1M⊕, R=11.9R⊕,
ρ=0.08g/cm3, Teq=960K). We observed one full transit and one
partial transit of this planet using the metastable helium filter on
Palomar/WIRC and found that the helium transits were 0.671%±0.079%
(8.5σ) deeper than the TESS transits, indicating an outflowing
atmosphere. We modeled the excess helium absorption using a
self-consistent 1D hydrodynamics code to constrain the thermal
structure of the outflow given different assumptions for the stellar
XUV spectrum. These calculations then informed a 3D simulation, which
provided a good match to the observations with a modest planetary
mass-loss rate of 1010.82g/s (Mp/M∼70Gyr). Superpuffs with
Mp≳10M⊕, like TOI-1420b and WASP-107b, appear perfectly capable
of retaining atmospheres over long timescales; therefore, these
planets may have formed with the unusually large envelope mass
fractions they appear to possess today. Alternatively, tidal
circularization could have plausibly heated and inflated these
planets, which would bring their envelope mass fractions into better
agreement with expectations from core-nucleated accretion.
Description:
We took photometric observations with the Wide-field InfraRed Camera
(WIRC) on the Hale 200inch Telescope at Palomar Observatory in J-band.
Objects:
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RA (2000) DE Designation(s)
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21 31 45.91 +66 20 55.9 TOI-1420b = TOI-1420.01
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig2.dat 24 442 The two phase-folded WIRC light curves of TOI-1420b
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See also:
J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008)
J/A+A/493/639 : Velocity curves of HD 40307 (Mayor+, 2009)
J/ApJS/214/25 : Rosseland & Planck gaseous mean opacities (Freedman+, 2014)
J/A+A/586/A75 : Simulations of hot gas planets atmospheres (Salz+, 2016)
J/MNRAS/466/1868 : Neptune-like planets low-density overabund (Cubillos+ 2017)
J/AJ/156/89 : RVs & predicted transit-times for K2-24 system (Petigura+, 2018)
J/AJ/160/201 : Infrared transmission spectrum for Kepler-79d (Chachan+, 2020)
J/AJ/159/57 : HST spectroscopic LCs of Kepler 51b & 51d (Libby-Roberts+, 2020)
J/AJ/159/278 : He-filter observations WASP-69b & WASP-52b (Vissapragada+, 2020)
J/AJ/161/70 : Radial velocities WASP-107 with HIRES & CORALIE (Piaulet+, 2021)
J/AJ/161/119 : The TESS-Keck survey. IV. Rvel for WASP-107 (Rubenzahl+, 2021)
J/AJ/165/48 : Transit times for Kepler-289 b, c and d (Greklek-McKeon+, 2023)
J/AJ/166/181 : HARPS-N and NEID radial velocities of TOI-1420 (Yoshida+, 2023)
Byte-by-byte Description of file: fig2.dat
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Bytes Format Units Label Explanations
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1- 1 I1 --- Day [1/2] Day identifier (1)
3- 10 F8.5 d Time [-0.18/0.2] Time from transit center
12- 17 F6.4 --- Flux [0.96/1.02] Relative flux
19- 24 F6.4 --- e_Flux [0.004/0.02] Uncertainty in Flux
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Note (1): Identifier as follows:
1 = 2022 June 30 from 05:17 to 12:02 UT.
2 = 2022 July 21 from 05:28 to 11:08 UT.
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From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 31-May-2024