J/AJ/170/216 Obs. precision estimation for exoplanets atmos. study (Burt+, 2025)
A new approach to compiling exoatmospheric target lists and quantifying the
ground-based resources needed to vet them.
Burt J.A., Zellem R.T., Ciardi D.R., Kanodia S., Bryden G., Kataria T.,
Pearson K.A., Christiansen J.L., Beichman C., Fulton B.J., Swain M.
<Astron. J., 170, 216 (2025)>
=2025AJ....170..216B 2025AJ....170..216B
ADC_Keywords: Exoplanets; Photometry; Optical; Stars, masses; Stars, diameters;
Abundances; Models, atmosphere
Keywords: Exoplanets ; Transmission spectroscopy ; Radial velocity ; Surveys ;
Transit photometry
Abstract:
Transiting exoplanet atmospheric characterization is currently in a
golden age as dozens of exoplanet atmospheres are being studied by
NASA's Hubble and James Webb Space Telescopes. This trend is expected
to continue with NASA's Pandora Smallsat and Roman Space Telescope and
ESA's Ariel mission (all expected to launch within this decade) and
NASA's Habitable Worlds Observatory (expected to launch in the early
2040s), all of which are centered around studying the atmospheres of
exoplanets. Here, we explore a new approach to constructing
large-scale exoatmospheric survey lists, which combines the use of
traditional transmission/emission spectroscopy figures of merit with a
focus on more evenly sampling planets across a range of radii and
equilibrium temperatures. After assembling a sample target list
comprised of 750 transmission spectroscopy targets and 150 emission
spectroscopy targets, we quantify the potential time lost to stale
transit and eclipse ephemerides and find that hundreds of hours of
space-based observing could be wasted given current uncertainties in
orbital periods, transit epochs, and orbital eccentricities. We
further estimate the amount of ground-based telescope time necessary
to obtain sufficiently precise exoplanet masses and find that it
exceeds 100 nights of 10m telescope time. Based upon these findings,
we provide a list of recommendations that would make community efforts
for the preparation and interpretation of atmospheric characterization
endeavors more effective and efficient. The strategies we recommend
here can be used to support both current (e.g., Hubble Space Telescope
and JWST) and future exoplanet atmosphere characterization missions
(e.g., Pandora, Ariel, Roman, and the Habitable Worlds Observatory).
Description:
When selecting transiting exoplanets for atmospheric characterization,
there are two relevant populations of potential targets.
The first is the set of confirmed, transiting exoplanets whose
existence and some subset of physical properties have been verified
via follow-up observing efforts and then published in the
peer-reviewed literature. To capture the current state of known
exoplanets, we queried the NASA Exoplanet Archive's Planetary Systems
Composite Data Catalog (http://exoplanetarchive.ipac.caltech.edu/)
NASA Exoplanet Science Institute, 2020a; accessed 2025 May 21) and
obtained a list of all "confirmed exoplanets," which includes
statistically validated planets.
The second population is the set of exoplanet candidates that have not
yet been confirmed via follow-up observations. To incorporate these
objects, we downloaded the current list of TESS objects of interest
(TOIs) from the TESS Exoplanet Vetter (TEV) website (http://tev.mit.edu/;
accessed 2025 May 21). We supplement this list with the most recent
TOI disposition for each candidate from the Exoplanet Follow-up
Observing Program (ExoFOP) website (http://exofop.ipac.caltech.edu/tess/).
To the TESS targets, we add the Kepler objects of interest (KOIs)
included in the Cumulative KOI Table (NASA Exoplanet Archive, 2019;
accessed 2024 June 5).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
fig1.dat 126 917 Mass and radius measurements for our sample of
917 confirmed planet (Data behind Figure 1)
fig3.dat 392 5843 Physical and orbital parameters of known and
TESS/Kepler planet candidates, and their host stars
(Data behind Figure 3)
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
J/AJ/141/166 : HATNet variability survey of K and M dwarfs (Hartman+, 2011)
J/ApJ/796/48 : Potential exoplanet targets: Palomar/TripleSpec (Zellem+, 2014)
J/ApJS/217/31 : Kepler planetary candidates. VI. 4yr Q1-Q16 (Mullally+, 2015)
J/ApJ/822/86 : False positive probabilities Q1-Q17 DR24 KOIs (Morton+, 2016)
J/ApJ/831/64 : Mass-metall. relation for giant planets (Thorngren+, 2016)
J/AJ/156/82 : RV characterization of TESS planets (Cloutier+, 2018)
J/MNRAS/474/5158 : Stars with hot Jupiter exoplanets (Goyal+, 2018)
J/AJ/157/242 : Updated study of potential targets for Ariel (Edwards+, 2019)
J/AJ/161/130 : List of 100 targets for NEID Earth Twin Survey (Gupta+, 2021)
J/MNRAS/507/1847 : A HARPS-N mass for the elusive Kepler-37d (Rajpaul+, 2021)
J/AJ/164/15 : Exoplanets as Ariel's potential targets (Edwards+, 2022)
J/AJ/164/178 : Archival radial velocities of HD 80606 (Pearson+, 2022)
J/MNRAS/510/3449 : KOI planets and KIC stars from Kepler DR25 (Bashi+, 2022)
J/AJ/163/171 : The EXPRES Stellar Signals Project. II. RVel (Zhao+, 2022)
J/ApJS/265/4 : ExoClock proj. III. 450 exoplanet ephemerides (Kokori+, 2023)
J/AJ/167/233 : Best-in-class TOIs for atmos. characterisation (Hord+, 2024)
http://exoplanetarchive.ipac.caltech.edu/ : NASA Exoplanet Archive website
http://tev.mit.edu/ : TESS Exoplanet Vetter (TEV) website
http://exofop.ipac.caltech.edu/tess/ : Exoplanet Follow-up Observing Program
(ExoFOP) website
Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 25 A25 --- Planet Planet name
27- 44 F18.8 d Per [0.28/4.02e+8]? Planet orbital period (1)
46- 51 F6.3 Rgeo Rp [0.64/22.76] Planetary radius (1)
53- 57 F5.3 Rgeo E_Rp [0.01/7.4] Upper uncertainty on Rp (1)
59- 64 F6.3 Rgeo e_Rp [0/7.18] Lower uncertainty on Rp (1)
66- 78 F13.9 --- Rp-sigma [2.18/370.8] Radius sigma
80- 89 F10.5 Mgeo Mp [0.07/6883.91] Planetary mass (1)
91- 100 F10.5 Mgeo E_Mp [0.012/1000] Upper uncertainty on Mp (1)
102- 112 F11.5 Mgeo e_Mp [0.012/1000] Lower uncertainty on Mp (1)
114- 126 F13.9 --- Mp-sigma [2/168.22] Mass sigma
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Note (1): Taken from NASA Exoplanet Archive's Confirmed Planets Table,
DOI: 10.26133/NEA12, accessed December 13, 2023.
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Byte-by-byte Description of file: fig3.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name Object of interest designation, TESS
(IV/39) or KOI (J/ApJS/217/31)
21- 29 A9 --- Disp Disposition from NASA Exoplanet
Archive and TESS Follow Up Observing
Program (3)
31- 44 F14.9 d Per [0.16/1693.67] Planet orbital period
46- 56 E11.9 d e_Per [0/0.94] Uncertainty in Per
58- 68 F11.3 d Epoch [2.45e+6/2.47e+6] Time of conjunction,
Barycentric Julian Date
70- 80 E11.9 d e_Epoch [2e-7/1.62] Uncertainty in Epoch
82- 93 F12.9 h Dur [0.13/34.84]? Transit duration
95- 106 F12.9 Rgeo Rp [0.69/22.76] Planetary radius
108- 121 F14.9 --- a/Rstar [0.98/1772]? Ratio, orbital semi-major
axis to stellar radius
123- 133 E11.9 --- e [0/0.996] Planetary eccentricity
135- 142 E8.6 --- e_e [0/0.42]? Uncertainty in e
144- 157 F14.9 deg omega [-210/359.89] Longitude of periastron
159- 166 F8.4 deg e_omega [0/245]? Uncertainty in omega
168- 179 E12.9 --- ecosw [-0.71/0.7] Planetary eccentricity *
cos omega
181- 182 A2 --- r_e Reference on e (1)
184- 196 F13.8 Mgeo Mp [0.63/7310.06] Planet mass
198- 209 F12.8 Mgeo e_Mp [0.05/635.66]? Uncertainty in Mp
211- 224 F14.9 m/s K [1/2277.39] RV Semi-amplitude (2)
226 I1 --- Mp-sigma-need [0/5] Required mass measurement
precision (mass-sigma-needed)
228- 240 F13.9 --- Mp-sigma [0/168.22]? Current planet mass
measurement precision
242- 252 F11.9 [cm/s2] logg-p [0.2/3.97] Log of planetary surface
gravity
254- 266 F13.8 K Teq-p [62.78/2740] Planet equilibrium
temperature (2)
268- 274 F7.2 K Teff [2839/6249] Host Star Effective
Temperature
276- 283 F8.6 Msun Mstar [0.13/2.74] Host star mass
285- 292 F8.6 Rsun Rstar [0.013/8.99] Host star radius
294- 300 F7.4 [-] [Fe/H] [-0.95/0.56]? Host star [Fe/H]
(metStar)
302- 312 F11.7 deg RAdeg Right ascension (J2000)
314- 324 F11.7 deg DEdeg Declination (J2000)
326- 334 F9.6 mag Vmag [5.56/18] V band (Vega) magnitude
336- 344 F9.6 mag Hmag [3.46/15.43] 2MASS (II/246) H band
(Vega) magnitude
346- 350 F5.2 [-] [C/O]atm [-0.26] Log of the atmospheric carbon
to oxygen ratio (logCtoO)
352- 356 F5.3 --- mu [2.35/8.99] Mean molecular weight,
atomic molecular units (mmw) (2)
358- 368 E11.9 --- FoM-trans [3.07e-5/27.26] Transmission
spectroscopy figure of merit
370- 380 E11.9 --- FoM-emiss [1.39e-59/0.21] Emission spectroscopy
figure of merit
382- 392 E11.9 --- Depth [2.11e-61/5.59e-3] Eclipse depth
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Note (1): Reference as follows:
EA = NASA Exoplanet Archive (18 occurrences)
SH = Shabram+ (2016ApJ...820...93S 2016ApJ...820...93S) relation (5825 occurrences)
Note (2): Listed value is either published or predicted.
Note (3): Disposition (see http://astrodennis.com/TFOP_SG1_Guidelines_Latest.pdf
for in-depth explanations) as follows:
CANDIDATE = Candidate; 394 occurrences
CPC = Cleared Planet Candidate; 108 occurrences
CPC- = Cleared Planet Candidate, but the follow-up aperture is
contaminated; 18 occurrences
CPC? = Cleared Planet Candidate?; 9 occurrences
KP = Known Planet; 2276 occurrences
PC = Planet Candidate; 834 occurrences
PPC = Promising Planet Candidate; 10 occurrences
VP = Validated Planet; 175 occurrences
VPC = Verified Planet Candidate; 791 occurrences
VPC+ = Verified Planet Candidate, with no obvious depth chromaticity;
863 occurrences
VPC+? = Verified Planet Candidate, with no obvious depth chromaticity?;
66 occurrences
VPC- = Verified Planet Candidate, but the follow-up aperture is
contaminated; 155 occurrences
VPC-+ = Verified Planet Candidate, with no obvious depth chromaticity, but
the follow-up aperture is contaminated; 35 occurrences
VPC-? = Verified Planet Candidate, but the follow-up aperture is
contaminated?; 11 occurrences
VPC? = Verified Planet Candidate?; 98 occurrences
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Robin Leichtnam [CDS] 16-Jul-2026