J/AJ/167/282 TESS/HIRES radial velocity follow up of TOI-1824 (Lange+, 2024)
The TESS-Keck Survey.
VII. A Superdense Sub-Neptune Orbiting TOI-1824.
Lange S., Murphy J.M.A., Batalha N.M., Crossfield I.J.M., Dressing C.D.,
Fulton B., Howard A.W., Huber D., Isaacson H., Kane S.R., Petigura E.A.,
Robertson P., Weiss L.M., Behmard A., Beard C., Blunt S., Brinkman C.L.,
Chontos A., Dai F., Dalba P.A., Fetherolf T., Giacalone S., Hill M.L.,
Holcomb R., Lubin J., MacDougall M.G., Mayo A.W., Mocnik T.,
Pidhorodetska D., Polanski A.S., Rice M., Rosenthal L.J., Rubenzahl R.A.,
Scarsdale N., Turtelboom E.V., Van Zandt J., Ciardi D.R., Boyle A.W.
<Astron. J., 167, 282 (2024)>
=2024AJ....167..282L 2024AJ....167..282L
ADC_Keywords: Exoplanets; Spectra, optical; Radial velocities
Keywords: Radial velocity ; Exoplanets ; Transit photometry
Abstract:
We confirm a massive sub-Neptune-sized planet on a P=22.8 days orbit
around the star TOI-1824 (Teff=5200 K, V=9.7 mag). TESS first
identified TOI-1824 b (formerly TOI-1824.01) as an object of interest
in 2020 April after two transits in Sector 22 were matched with a
single transit in Sector 21. TOI-1824 was subsequently targeted for
ground-based Doppler monitoring with Keck-HIRES and APF-Levy. Using a
joint model of the TESS photometry, radial velocities, and Ca ii H and
K emission measurements as an activity indicator, we find that
TOI-1824b is an unusually dense sub-Neptune. The planet has a radius
Rp=2.63±0.15R⊕ and mass Mp=18.5±3.2M⊕, implying a
bulk density of 5.6±1.4g/cm3. TOI-1824 b's mass and radius
situate it near a small group of "superdense sub-Neptunes"
(Rp≲3R⊕ and Mp≳20M⊕). While the formation mechanism of
superdense sub-Neptunes is a mystery, one possible explanation is the
constructive collision of primordial icy cores; such giant impacts
would drive atmospheric escape and could help explain these planets'
apparent lack of massive envelopes. We discuss TOI-1824b in the
context of these overdense planets, whose unique location in the
exoplanet mass-radius plane make them a potentially valuable tracer of
planet formation.
Description:
We obtained 58 high-resolution spectra of TOI-1824 with Keck-HIRES
between UT 2020 June 2 and UT 2022 July 31. The observations have a
median exposure time of 307s and a median S/N of 155/pixel at 5500AA.
(R=45000)
We also obtained spectra of TOI-1824 using the Levy spectrograph
mounted on the 2.4m APF telescope at Lick Observatory. We obtained 275
high-resolution spectra of TOI-1824 with APF-Levy between UT 2020
April 28 and UT 2023 February 1. The observations had a median
exposure time of 1800s and a median S/N of approximately 57/pixel at
5500AA. The observations were taken with the W decker (1x3", R=95000).
Objects:
-----------------------------------------------------------
RA (2000) DE Designation(s) (Period)
-----------------------------------------------------------
13 10 55.48 +61 44 41.2 TOI-182 = AG+62 782 (P=22.8d)
-----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 46 333 TOI-1824 radial velocities and SHK values
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See also:
III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010)
J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)
J/ApJ/764/3 : Hα indices in M low-mass stars (Robertson+, 2013)
J/ApJS/210/20 : Small Kepler planets radial velocities (Marcy+, 2014)
J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)
J/ApJ/825/19 : Mass-radius relationship planets with Rp<4 (Wolfgang+, 2016)
J/AJ/154/109 : California-Kepler Survey. III. Planet radii (Fulton+, 2017)
J/AJ/153/71 : Kepler follow-up obs program. I. Imaging (Furlan+, 2017)
J/AJ/154/5 : Transit timing variations 145 Kepler planets (Hadden+, 2017)
J/ApJ/844/102 : KIC star plxes from asteroseismology vs Gaia (Huber+, 2017)
J/AJ/153/257 : Comoving stars in Gaia DR1 (Oh+, 2017)
J/AJ/154/107 : California-Kepler Survey. I. 1305 stars (Petigura+, 2017)
J/ApJ/836/77 : Library of high-S/N optical spectra of FGKM stars (Yee+, 2017)
J/AJ/155/203 : HARPS-N RVs & activity indicators Kepler-1655 (Haywood+, 2018)
J/A+A/623/A114 : Light curve of K2-292 (HD 119130) (Luque+, 2019)
J/AJ/159/280 : Gaia-Kepler star properties cat. I. KIC stars (Berger+, 2020)
J/AJ/159/241 : TESS-Keck Survey. I. HD332231 Radial Velocities (Dalba+, 2020)
J/ApJS/254/39 : Exoplanet candidates from TESS first 2yr obs (Guerrero+, 2021)
J/AJ/162/265 : TESS-Keck survey. VI. HIP-97166 rvel (Macdougall+, 2021)
J/AJ/161/70 : Rvel for WASP-107 with HIRES & CORALIE (Piaulet+, 2021)
J/AJ/162/89 : HIRES radial velocity follow up for Kepler-129 (Zhang+, 2021)
J/AJ/163/160 : Properties of 170 TOI hosts and companions (Behmard+, 2022)
J/AJ/163/61 : TESS-Keck Survey VIII. TOI-2180 radial velocity (Dalba+, 2022)
J/AJ/163/101 : TESS-Keck survey. IX. Rvel of HD1919139 (Lubin+, 2022)
J/other/Sci/377.1211 : RV and LC of 8 M dwarf stars with planets (Luque+, 2022)
J/MNRAS/511/1043 : Sub-Neptunes transiting TOI-1064 (Wilson+, 2022)
J/AJ/166/62 : New HIRES radial velocity data for V1298 Tau (Blunt+, 2023)
J/AJ/167/70 : TESS-Keck Survey. XVII. TOI-1136 rvel (Beard+, 2024)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 F14.6 d BJD [2458967/2459978] Barycentric Julian Date at TDB
16- 21 F6.2 m.s-1 RVel [-26.12/30.35] Radial velocity, m/s (1)
23- 26 F4.2 m.s-1 e_RVel [1.12/6.78] Uncertainty in RVel (2)
28- 32 F5.3 --- SHK [0.33/0.406]? Mt. Wilson CaII HK activity index
34- 38 F5.3 --- e_SHK [0.002/0.002]? Uncertainty in SHK
40- 46 A7 --- Tel Telescope used; APF or HIRES
--------------------------------------------------------------------------------
Note (1): Instrumental offsets have not been applied to the RVel values
listed here.
Note (2): The RV errors represent measurement uncertainty and have not
yet been added in quadrature with the corresponding instrument
jitter values resulting from our models of the data
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Dalba et al. Paper I. 2020AJ....159..241D 2020AJ....159..241D Cat. J/AJ/159/241
Weiss et al. Paper II. 2021AJ....161...56W 2021AJ....161...56W Cat. J/AJ/161/56
Dai et al. Paper III. 2020AJ....160..193D 2020AJ....160..193D
Rubenzahl et al. Paper IV. 2021AJ....161..119R 2021AJ....161..119R Cat. J/AJ/161/119
Scarsdale et al. Paper V. 2021AJ....162..215S 2021AJ....162..215S Cat. J/AJ/162/215
MacDougall et al. Paper VI. 2021AJ....162..265M 2021AJ....162..265M Cat. J/AJ/162/265
Lange et al. Paper VII. 2024AJ....167..282L 2024AJ....167..282L This catalog
Dalba et al. Paper VIII. 2022AJ....163...61D 2022AJ....163...61D Cat. J/AJ/163/61
Lubin et al. Paper IX. 2022AJ....163..101L 2022AJ....163..101L Cat. J/AJ/163/101
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Chontos et al. Paper XII. 2022AJ....163..297C 2022AJ....163..297C
MacDougall et al. Paper XIII. 2022AJ....164...97M 2022AJ....164...97M Cat. J/AJ/164/97
Van Zandt et al. Paper XIV. 2023AJ....165...60V 2023AJ....165...60V Cat. J/AJ/165/60
MacDougall et al. Paper XV. 2023AJ....166...33M 2023AJ....166...33M Cat. J/AJ/166/33
Murphy et al. Paper XVI. 2023AJ....166..153M 2023AJ....166..153M Cat. J/AJ/166/153
Beard et al. Paper XVII. 2024AJ....167...70B 2024AJ....167...70B Cat. J/AJ/167/70
Desai et al. Paper XVIII. 2024AJ....167..194D 2024AJ....167..194D Cat. J/AJ/167/194
Hill et al. Paper XIX. 2024AJ....167..151H 2024AJ....167..151H
Polanski et al. Paper XX. 2024ApJS..272...32P 2024ApJS..272...32P
Pidhorodetska et al. Paper XXII. 2024AJ....168..135P 2024AJ....168..135P Cat. J/AJ/168/135
(End) Prepared by [AAS], Coralie Fix [CDS], 17-Jun-2024