J/AJ/168/118 Relative RVs for KELT-24 taken from MINERVA (Giovinazzi+, 2024)
Trials and tribulations in the reanalysis of KELT-24 b: a case study for the
importance of stellar modeling.
Giovinazzi M.R., Cale B., Eastman J.D., Rodriguez J.E., Blake C.H.,
Stassun K.G., Vanderburg A., Kunimoto M., Kraus A.L., Twicken J.,
Beatty T.G., Dedrick C.M., Horner J., Johnson J.A., Johnson S.A.,
McCrady N., Plavchan P., Sliski D.H., Wilson M.L., Wittenmyer R.A.,
Wright J.T., Johnson M.C., Rose M.E., Cornachione M.
<Astron. J., 168, 118 (2024)>
=2024AJ....168..118G 2024AJ....168..118G
ADC_Keywords: Radial velocities; Stars, double and multiple; Exoplanets;
Spectra, optical
Keywords: Exoplanet systems ; Stellar properties ; Multiple stars
Abstract:
We present a new analysis of the KELT-24 system, comprising a
well-aligned hot Jupiter, KELT-24 b, and a bright (V=8.3), nearby
(d=96.9pc) F-type host star. KELT-24 b was independently discovered by
two groups in 2019, with each reporting best-fit stellar parameters
that were notably inconsistent. Here, we present three independent
analyses of the KELT-24 system, each incorporating a broad range of
photometric and spectroscopic data, including eight sectors of
Transiting Exoplanet Survey Satellite (TESS) photometry and more than
200 new radial velocities (RVs) from the MINiature Exoplanet Radial
Velocity Array. Two of these analyses use KELT-24's observed spectral
energy distribution (SED) through a direct comparison to stellar
evolutionary models, while our third analysis assumes an unknown
additional body contributing to the observed broadband photometry and
excludes the SED. Ultimately, we find that the models that include the
SED are a poor fit to the available data, so we adopt the system
parameters derived without it. We also highlight a single transit-like
event observed by TESS, deemed likely to be an eclipsing binary bound
to KELT-24, that will require follow-up observations to confirm. We
discuss the potential of these additional bodies in the KELT-24 system
as a possible explanation for the discrepancies between the results of
the different modeling approaches, and explore the system for
longer-period planets that may be weakly evident in the RV
observations. The comprehensive investigations that we present not
only increase the fidelity of our understanding of the KELT-24 system
but also serve as a blueprint for future stellar modeling in global
analyses of exoplanet systems.
Description:
The Kilodegree Extremely Little Telescope (KELT) used two 42mm
telescopes, one being KELT-North (Winer Observatory outside of
Sonoita, Arizona) and the other KELT-South (South African Astronomical
Observatory in Sutherland, South Africa). KELT-24 was observed
10181 times between 2013 September 24 and 2017 December 31 across two
KELT-North (KN) fields KN26 and KN27. See Section 2.1.
TESS observed KELT-24 (TIC 349827430) with two-minute cadence in eight
sectors, spanning 2019 Jul 18 to 2023 Jan 18. The complete data set of
all sectors used in this analysis can be found at MAST:10.17909/4agy-rx54
See Section 2.2.
Rodriguez+ 2019, J/AJ/158/197 (R2019) obtained 59 spectra (with a
resolving power of R∼44000) of KELT-24 from the Tillinghast Reflector
Echelle Spectrograph (TRES). Here, we add one additional
out-of-transit spectrum from TRES taken on 2022 June 15.
See Section 2.3.
Between 2018 April and 2019 May, the Hertzsprung Stellar Observation
Network Group (SONG) telescope collected 92 RV measurements of
KELT-24, 24 of which were taken with high cadence during a transit on
2018 May 29. See Section 2.4.
R2019 published 37 RV measurements of KELT-24 from the MINiature
Exoplanet Radial Velocity Array (MINERVA), all taken on 2019 March 31
to measure KELT-24 b's DT signal. The MINERVA array is a set of four
PlaneWave CDK700 0.7m telescopes at the the Fred Lawrence Whipple
Observatory (FLWO) on Mt. Hopkins in Arizona. Each exposure consists
of spectra from all four telescopes.
For the purpose of updating the KELT-24 system, we collected 201 new
RV measurements from MINERVA between 2019 Mar 26 and 2020 Feb 2. Of
these, nine are found to have incidentally been taken during transit
and are used to help further constrain KELT-24 b's projected
obliquity. See Section 2.5
An epoch of adaptive optics (AO) imaging from the Near Infrared
Camera2 (NIRC2) on the W. M. Keck Observatory was obtained by R2019 on
2019 May 12 in the Brγ passband. Here, we reprocess that same
image. We also publish an AO observation of the KELT-24 system taken
on 2019 June 10. See Section 2.6.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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10 47 38.35 +71 39 21.1 KELT-24 = TYC 4388-1652-1 (P=5.5514929)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 31 201 Relative RVs for KELT-24 taken from MINERVA
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See also:
VI/39 : Model Atmospheres (Kurucz, 1979)
III/135 : Henry Draper Catalogue and Extension (Cannon+ 1918-1924; ADC 1989)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/281 : 2MASS 6X Point Source Working Database / Catalog (Cutri+ 2006)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
J/ApJ/646/505 : Catalog of nearby exoplanets (Butler+, 2006)
J/ApJ/720/1118 : i-band photometry of HAT-P-16 (Buchhave+, 2010)
J/ApJ/718/810 : Astrometry & Photometry in the Arches cluster (Stolte+, 2010)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
J/A+A/529/A75 : Limb-darkening coefficients (Claret+, 2011)
J/ApJ/757/18 : Rvels for 16 hot Jupiter host stars (Albrecht+, 2012)
J/ApJ/756/L33 : Radial velocities of 2 hot Jupiters in Praesepe (Quinn+, 2012)
J/A+A/549/A109 : HARPS XXXI. The M-dwarf sample (Bonfils+, 2013)
J/A+A/550/A53 : Public code ARoME for modeling the RM effect (Boue+, 2013)
J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)
J/ApJ/818/43 : Stellar surface gravity measures of KIC stars (Bastien+, 2016)
J/AJ/152/180 : Bol. fluxes of eclipsing binaries in Tycho-2 (Stassun+, 2016)
J/AJ/153/136 : Planets and host stars with Gaia parallaxes (Stassun+, 2017)
J/AJ/156/234 : KELT transit false positive catalog for TESS (Collins+, 2018)
J/ApJ/856/23 : BANYAN. XI. The BANYAN Σ algorithm (Gagne+, 2018)
J/A+A/631/A76 : MASCARA-3b radial and light curves (Hjorth+, 2019)
J/ApJ/871/63 : How to constrain your M dwarf. II. Nearby bin. (Mann+, 2019)
J/AJ/158/197 : Radial velocities & light curves of KELT-24 (Rodriguez+, 2019)
J/ApJ/904/140 : R147 members & rot. data for 5 other cl. (Curtis+, 2020)
J/AcA/70/181 : Search for Planets in Hot Jupiter Systems (Maciejewski+, 2020)
J/ApJS/254/42 : Hipparcos-Gaia (EDR3) Catalog of Accelerations (Brandt, 2021)
J/ApJS/254/39 : Exoplanet candidates from TESS first 2yr obs (Guerrero+, 2021)
J/AJ/161/194 : LCs & RVs of 5 exoplanets from TESS disc. (Rodriguez+, 2021)
J/AJ/164/70 : TESS Grand Unified Hot Jupiter Survey I. (Yee+, 2022)
J/ApJS/265/1 : TESS Grand Unified Hot Jupiter Surveys. II. (Yee+, 2023)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD [2458568.7/2458881.9] Barycentric Julian Date; TDB
15- 21 F7.2 m/s RVel [-737/804] Radial velocity
23- 28 F6.2 m/s e_RVel [47.6/665.4] Uncertainty in RVel
30- 31 A2 --- Inst Instrument (1)
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Note (1): Where T# denotes the telescope number for MINERVA. A summary of
all radial velocities for KELT-24 is provided in Table 4:
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Instrument Nobs Dates σRV-
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TRES 25 2019 Mar 06-2022 Jun 15 32.90
SONG 65 2018 Apr 14-2019 Jun 09 40.00
MINERVA_T1 63 2019 Mar 26-2020 Feb 02 125.13
MINERVA_T2 47 2019 Mar 26-2020 Jan 11 108.02
MINERVA_T3 54 2019 Mar 26-2019 Nov 24 110.90
MINERVA_T4 37 2019 Mar 28-2020 Jan 11 148.83
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σRV- is the average RV error for each instrument, in m/s
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-Nov-2024