J/AJ/165/267 O2 levels in Nearby Transiting Exoplanets (Hardegree-Ullman+, 2023)
Bioverse; A Comprehensive Assessment of the Capabilities of Extremely Large
Telescopes to Probe Earth-like O2 Levels in Nearby Transiting Habitable-zone
Exoplanets.
Hardegree-Ullman K.K., Apai D., Bergsten G.J., Pascucci I.,
Lopez-Morales M.
<Astron. J., 165, 267 (2023)>
=2023AJ....165..267H 2023AJ....165..267H
ADC_Keywords: Exoplanets; Stars, M-type; Spectra, optical
Keywords: Fundamental parameters of stars ; Exoplanet systems ;
Exoplanets ; Exoplanet atmospheres ; Biosignatures
Abstract:
Molecular oxygen is a strong indicator of life on Earth and may
indicate biological processes on exoplanets too. Recent studies
proposed that Earth-like O2 levels might be detectable on nearby
exoplanets using high-resolution spectrographs on future extremely
large telescopes (ELTs). However, these studies did not consider
constraints like relative velocities, planet occurrence rates, and
target observability. We expanded on past studies by creating a
homogeneous catalog of 286391 main-sequence stars within 120pc using
Gaia DR3 and used the Bioverse framework to simulate the likelihood of
finding nearby transiting Earth analogs. We also simulated a survey of
M dwarfs within 20pc accounting for η⊕ estimates, transit
probabilities, relative velocities, and target observability to
determine how long ELTs and theoretical 50-100m ground-based
telescopes need to observe to probe for Earth-like O2 levels with an
R=100000 spectrograph. This would only be possible within 50yr for up
to ∼21% of nearby M-dwarf systems if a suitable transiting
habitable-zone Earth analog was discovered, assuming signals from
every observable partial transit from each ELT can be combined. If so,
Earth-like O2 levels could be detectable on TRAPPIST-1 d-g within
16-55yr, respectively, and about half that time with an R=500000
spectrograph. These results have important implications for whether
ELTs can survey nearby habitable-zone Earth analogs for O2 via
transmission spectroscopy. Our work provides the most comprehensive
assessment to date of the ground-based capabilities to search for life
beyond the solar system.
Description:
We created a homogeneous catalog of 286391 main-sequence stars within
120pc using Gaia DR3 and used the Bioverse framework to simulate the
likelihood of finding nearby transiting Earth analogs. We also
simulated a survey of M-dwarfs within 20pc accounting for η⊕
estimates, transit probabilities, relative velocities, and target
observability to determine how long ELTs and theoretical 50-100m
ground-based telescopes need to observe to probe for Earth-like O2
levels with an R=100000 spectrograph.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 334 286391 Photo-astrometric properties of main sequence
stars within 120pc
table2.dat 59 1461 Habitable zone properties for M dwarfs within 20pc
table3.dat 123 1461 *Simulated average number of visible full transits
per year from each ELT for a hypothetical
habitable zone Earth-sized planet orbiting
M-dwarfs within 20pc
table4.dat 123 1461 *Simulated average number of visible partial
transits per year from each ELT for a
hypothetical habitable zone Earth-sized planet
orbiting M-dwarfs within 20pc
table5.dat 162 1461 Time span required to probe for Earth-like O2
levels at 3σ significance on a hypothetical
transiting habitable zone Earth analog orbiting
M-dwarfs within 20pc (full transits)
table6.dat 162 1461 Time span required to probe for Earth-like O2
levels at 3σ significance on a hypothetical
transiting habitable zone Earth analog orbiting
M-dwarfs within 20 pc (partial transits)
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Note on table3.dat and table4.dat: For each ELT, we consider the
number of full transits visible from the ground per year with no
relative system velocity requirements (None), considering relative
system velocities required to observe in the O2 A and IR bands
separately, when relative system velocities allow both A and IR band
observations, and the best case O2 band scenario, which is the
maximum of the A, IR, and A+IR columns. Blanks indicate our
simulations yielded no observable transits for that particular
scenario.
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See also:
B/simbad : Simbad objects catalogue (M.Wenger 2000)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/MNRAS/325/1365 : Solarneighbourhood metallicity distribution (Haywood+, 2001)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)
J/A+A/533/A141 : Stellar parameters for 582 HARPS FGK stars (Sousa+, 2011)
J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)
J/ApJ/783/4 : Prop. of Kepler multi-planet candidate systems (Wang+, 2014)
J/ApJ/807/45 : Pot. habitable planets orbiting M dwarfs (Dressing+, 2015)
J/ApJ/804/64 : Empirical and model parameters of 183 M dwarfs (Mann+, 2015)
J/ApJ/814/130 : Planet occurrence rates calculated for KOIs (Mulders+, 2015)
J/ApJS/220/16 : SpeX NIR survey of 886 nearby M dwarfs (Terrien+, 2015)
J/ApJ/818/153 : MEarth photometry; nearby Mdwarf magnitudes (Dittmann+, 2016)
J/AJ/152/8 : Impact of stellar mult. on planetary systems I (Kraus+, 2016)
J/AJ/154/109 : California-Kepler Survey. III. Planet radii (Fulton+, 2017)
J/AJ/153/71 : Kepler follow-up observation program. I. (Furlan+, 2017)
J/ApJS/239/2 : Simulated exoplanets from TESS list targets (Barclay+, 2018)
J/AJ/158/87 : 86 cool dwarfs observed K2 Campaigns 1-17 (Dressing+, 2019)
J/AJ/158/75 : Mid-type Mdwarfs planet occurrence (Hardegree-Ullman+, 2019)
J/ApJ/871/63 : Constrain your M dwarf. II. Nearby binaries (Mann+, 2019)
J/AJ/157/216 : Stellar multiplicity of Mdwarfs within 25pc (Winters+, 2019)
J/A+A/624/A49 : Spectra Earth-like planets around Mdwarfs (Wunderlich+, 2019)
J/ApJS/247/28 : K2 parameters from Gaia & LAMOST (Hardegree-Ullman+, 2020)
J/A+A/642/A121 : LHS1140 radial velocity data (Lillo-Box+, 2020)
J/AJ/160/19 : 827 ultracool dwarfs with K2 (Sagear+, 2020)
J/A+A/641/A170 : Ultracool dwarf K2 light curves (Sestovic+, 2020)
J/AJ/161/36 : 117 exoplanets in habitable zone Kepler DR25 (Bryson+, 2021)
J/MNRAS/506/150 : The GALAH+ Survey DR3 (Buder+, 2021)
J/A+A/649/A6 : Gaia Cat. of Nearby Stars - GCNS (Gaia collaboration, 2021)
J/A+A/649/A3 : Gaia EDR 3 photometric passbands (Riello+, 2021)
J/A+A/667/A59 : LP 890-9 (TOI-4306) light curves and RVs (Delrez+, 2022)
J/A+A/664/A65 : Early-M dwarfs occurrence rates (Pinamonti+, 2022)
J/AJ/163/200 : Robo-AO of northern stars companions (Salama+, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- Gaia ? Gaia DR3 source identifier
21- 37 A17 --- 2MASS 2MASS identifier
39- 72 A34 --- Name Object name from SIMBAD
74- 84 F11.7 deg RAdeg [0/360] Right ascension (J2000)
86- 96 F11.7 deg DEdeg [-90/90] Declination (J2000)
98-107 F10.4 mas/yr pmRA [-4407/6766]? Proper motion in RA direction
109-116 F8.4 mas/yr e_pmRA [0.004/20]? Standard error in pmRA
118-128 F11.4 mas/yr pmDE [-5818/10363]? Proper motion in DE direction
130-137 F8.4 mas/yr e_pmDE [0.005/24]? Standard error in pmDE
139-146 F8.4 mag Gmag [2.68/21.1]? Gaia DR3 G-band mean magnitude
148-154 F7.4 mag e_Gmag [0.0002/0.3]? Error in Gmag
156-163 F8.4 mag BPmag [3.18/24.7]? Gaia DR3 integrated BP mean
magnitude
165-171 F7.4 mag e_BPmag [0.0005/3]? Error in BPmag
173-180 F8.4 mag RPmag [2.55/19.9]? Gaia DR3 integrated RP mean
magnitude
182-188 F7.4 mag e_RPmag [0.0004/3]? Error on RPmag
190-196 F7.3 mag Vmag [0.01/22.2]? Apparent V-band Vega magnitude
198-203 F6.3 mag e_Vmag [0.001/1]? Error in Vmag
205-211 F7.3 mag Ksmag [-2.01/17.4]? Apparent Ks band magnitude
213-218 F6.3 mag e_Ksmag [0.01/1]? Error in Ksmag
220-226 F7.3 pc Dist [1.3/120] Gaia DR3 based distance
228-234 F7.3 pc E_Dist [0/116] Upper uncertainty in Dist
236-241 F6.3 pc e_Dist [0/60] Lower uncertainty in Dist
243-246 I4 K Teff [2301/9903] Stellar effective surface
temperature
248-251 I4 K e_Teff [70/9074] Uncertainty in Teff
253-260 E8.3 Lsun Lum [2.84e-05/45.1] Stellar luminosity
262-269 E8.3 Lsun e_Lum [2.3e-06/29.6] Uncertainty in Lum
271-275 F5.3 Rsun Rad [0.09/2.5] Stellar radius
277-281 F5.3 Rsun e_Rad [0.003/3] Uncertainty in Rad
283-287 F5.3 Msun Mass [0.08/2.45] Stellar mass
289-293 F5.3 Msun e_Mass [0.003/0.7] Uncertainty in Mass
295-300 F6.2 --- RUWE [0.46/96.6]? Gaia DR3 renormalised unit
weight error
302-302 A1 --- GCNS T/F if Gaia Catalogue of Nearby Stars binary
(Gaia Collaboration+, 2021, J/A+A/649/A6)
304-304 A1 --- Gaiabin T/F if Gaia EDR3 binary;
El-Badry+, 2021MNRAS.506.2269E 2021MNRAS.506.2269E
306-306 A1 --- AObin T/F if Robo-AO binary;
Salama+, 2022, J/AJ/163/200
308-308 A1 --- DR3bin T/F if Gaia DR3 non-single star;
Gaia Collaboration+, 2022arXiv220605595G 2022arXiv220605595G
310-310 A1 --- SIMBADbin T/F if eclipsing or spectroscopic binary on
SIMBAD; Wenger+, 2000A&AS..143....9W 2000A&AS..143....9W
312-312 A1 --- Any-bin T/F if binary in any referenced catalog
314-322 F9.4 --- SVel [-862/796]? Systemic velocity
324-332 F9.4 --- e_SVel [0/999]? Uncertainty in SVel
334-334 I1 --- r_SVel [1/3]? Reference for systemic velocity (1)
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Note (1): References as follows:
1 = Katz+, 2022arXiv220605902K 2022arXiv220605902K
2 = Literature values from SIMBAD; Wenger+, 2000A&AS..143....9W 2000A&AS..143....9W
3 = This work.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 30 A30 --- Name Object name from SIMBAD
32- 36 F5.3 AU ainner [0.01/0.39] Inner edge of the habitable zone
38- 42 F5.3 AU aouter [0.03/0.7] Outer edge of the habitable zone
44- 47 F4.2 % Prob [0.6/3.18] Geometric transit probability (1)
49- 54 F6.2 d Period [5.54/179] Average orbital period (1)
56- 59 F4.2 h T14 [0.8/8.4] Average transit duration (1)
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Note (1): For a 1REarth planet in the middle of the star's habitable zone.
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Byte-by-byte Description of file: table[34].dat
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Bytes Format Units Label Explanations
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1- 30 A30 --- Name Object name from SIMBAD
32- 33 I2 --- Ntrans Approximate number of transits per year (1)
35- 39 F5.2 --- GMT-None ? Average expected number of
transits visible from the GMT per year
41- 45 F5.2 --- GMT-A ? Average expected number of
transits visible from the GMT (2)
47- 51 F5.2 --- GMT-IR ? Average expected number of
transits visible from the GMT (3)
53- 57 F5.2 --- GMT-A+IR ? Average expected number of
transits visible from the GMT (4)
59- 63 F5.2 --- GMT-Best ? Average expected number of
transits visible from the GMT (5)
65- 69 F5.2 --- TMT-None ? Average expected number of
transits visible from the TMT per year
71- 75 F5.2 --- TMT-A ? Average expected number of
transits visible from the TMT (2)
77- 81 F5.2 --- TMT-IR ? Average expected number of
transits visible from the TMT (3)
83- 87 F5.2 --- TMT-A+IR ? Average expected number of
transits visible from the TMT (4)
89- 93 F5.2 --- TMT-Best ? Average expected number of
transits visible from the TMT (5)
95- 99 F5.2 --- E-ELT-None ? Average expected number of
transits visible from the E-ELT per year
101-105 F5.2 --- E-ELT-A ? Average expected number of
transits visible from the E-ELT (2)
107-111 F5.2 --- E-ELT-IR ? Average expected number of
transits visible from the E-ELT (3)
113-117 F5.2 --- E-ELT-A+IR ? Average expected number of
transits visible from the E-ELT (4)
119-123 F5.2 --- E-ELT-Best ? Average expected number of
transits visible from the E-ELT (5)
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Note (1): For a habitable zone planet orbiting this star.
Note (2): Considering relative system velocities amenable to A-band observations
Note (3): Considering relative system velocities amenable to IRband observations
Note (4): Considering relative system velocities amenable to both A and IR-band
observations.
Note (5): Considering the best case scenario (A, IR, or A+IR) to minimize
observing time.
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Byte-by-byte Description of file: table[56].dat
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Bytes Format Units Label Explanations
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1- 30 A30 --- Name Object name from SIMBAD
32- 41 F10.2 yr GMT-A ? Years to detect O2 with GMT in A band
43- 52 F10.2 yr GMT-IR ? Years to detect O2 with GMT in IR band
54- 63 F10.2 yr GMT-A+IR ? Years to detect O2 with GMT in A+IR bands
65- 73 F9.2 yr TMT-A ? Years to detect O2 with TMT in A band
75- 83 F9.2 yr TMT-IR ? Years to detect O2 with TMT in IR band
85- 93 F9.2 yr TMT-A+IR ? Years to detect O2 with TMT in A+IR bands
95-103 F9.2 yr E-ELT-A ? Years to detect O2 with E-ELT in A band
105-113 F9.2 yr E-ELT-IR ? Years to detect O2 with E-ELT in IR band
115-123 F9.2 yr E-ELT-A+IR ? Years to detect O2 with E-ELT in A+IR bands
125-133 F9.2 yr Combined ? Years to detect O2 with combined signals
from ELTs
135-143 F9.2 yr 50m ? Years to detect O2 with a 50-m telescope
145-153 F9.2 yr 75m ? Years to detect O2 with a 75-m telescope
155-162 F8.2 yr 100m ? Years to detect O2 with a 100-m telescope
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 16-Oct-2023