J/A+A/624/A49 Spectra of Earth-like planets around M-dwarfs (Wunderlich+, 2019)
Detectability of atmospheric features of Earth-like planets in the habitable
zone around M dwarfs.
Wunderlich F., Godolt M., Grenfell J.L., Staedt S., Smith A.M.S.,
Gebauer S., Schreier F., Hedelt P., Rauer H.
<Astron. Astrophys. 624, A49 (2019)>
=2019A&A...624A..49W 2019A&A...624A..49W (SIMBAD/NED BibCode)
ADC_Keywords: Stars, M-type ; Stars, double and multiple ; Exoplanets ;
Spectra, infrared ; Models, atmosphere
Keywords: planets and satellites: atmospheres -
planets and satellites: detection -
planets and satellites: surfaces -
planets and satellites: terrestrial planets -
techniques: spectroscopic - stars: low-mass
Abstract:
The characterisation of the atmosphere of exoplanets is one of the
main goals of exoplanet science in the coming decades.
We investigate the detectability of atmospheric spectral features of
Earth-like planets in the habitable zone (HZ) around M dwarfs with the
future James Webb Space Telescope (JWST).
We used a coupled 1D climate-chemistry-model to simulate the influence
of a range of observed and modelled M-dwarf spectra on Earth-like
planets. The simulated atmospheres served as input for the calculation
of the transmission spectra of the hypothetical planets, using a
line-by-line spectral radiative transfer model. To investigate the
spectroscopic detectability of absorption bands with JWST we further
developed a signal- to-noise ratio (S/N) model and applied it to our
transmission spectra. High abundances of methane (CH4) and water
(H2O) in the atmosphere of Earth-like planets around mid to late M
dwarfs increase the detectability of the corresponding spectral
features compared to early M-dwarf planets. Increased temperatures in
the middle atmosphere of mid- to late-type M-dwarf planets expand the
atmosphere and further increase the detectability of absorption bands.
To detect CH4, H2O, and carbon dioxide (CO2) in the
atmosphere of an Earth-like planet around a mid to late M dwarf
observing only one transit with JWST could be enough up to a distance
of 4pc and less than ten transits up to a distance of 10pc. As a
consequence of saturation limits of JWST and less pronounced
absorption bands, the detection of spectral features of hypothetical
Earth-like planets around most early M dwarfs would require more than
ten transits. We identify 276 existing M dwarfs (including GJ 1132,
TRAPPIST-1, GJ 1214, and LHS 1140) around which atmospheric absorption
features of hypothetical Earth-like planets could be detected by
co-adding just a few transits. The TESS satellite will likely find new
transiting terrestrial planets within 15pc from the Earth. We show
that using transmission spectroscopy, JWST could provide enough
precision to be able to partly characterise the atmosphere of TESS
findings with an Earth-like composition around mid to late M dwarfs.
Description:
Effective heights for 11 hypothetical Earth-like planets around
different M-dwarfs and the Earth around the Sun in the range from
0.4-11.1um with a resolving power of 100.
Each data file corresponds to a different host star of the planet.
The host stars are: Sun - G2, GJ 832 - M1.5, GJ 176 - M2, GJ 581 -
M2.5, GJ 436 - M3, GJ 644 - M3, AD Leonis - M3.5, GJ 667C - M3.5, GJ
876 - M4, GJ 1214 - M4.5, Proxma Centauri - M5.5, and TRAPPIST-1 - M8.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 62 12 Host stars list
sun.dat 21 333 Effective heights for Earth around Sun
gj832.dat 21 333 Effective heights for planet around GJ 832
gj176.dat 21 333 Effective heights for planet around GJ 176
gj581.dat 21 333 Effective heights for planet around GJ 581
gj436.dat 21 333 Effective heights for planet around GJ 436
gj644.dat 21 333 Effective heights for planet around GJ 644
adleo.dat 21 333 Effective heights for planet around AD Leonis
gj667c.dat 21 333 Effective heights for planet around GJ 667C
gj876.dat 21 333 Effective heights for planet around GJ 876
gj1214.dat 21 333 Effective heights for planet around GJ 1214
proxcen.dat 21 333 Effective heights for planet around
Proxima Centauri
trappist.dat 21 333 Effective heights for planet around TRAPPIST-1
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See also:
J/A+A/482/989 : Spectropolarimetric model for Earth-like planets (Stam, 2008)
J/AJ/151/59 : Catalog of Earth-Like Exoplanet Survey Targets (Chandler+ 2016)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Name
20- 21 I2 h RAh ? Simbad right ascension (J2000.0)
23- 24 I2 min RAm ? Simbad right ascension (J2000.0)
26- 30 F5.2 s RAs ? Simbad right ascension (J2000.0)
32 A1 --- DE- ? Simbad declination sign (J2000.0)
33- 34 I2 deg DEd ? Simbad Declination (J2000.0)
36- 37 I2 arcmin DEm ? Simbad declination (J2000.0)
39- 42 F4.1 arcsec DEs ? Simbad declination (J2000.0)
45- 48 A4 --- SpType Spectral type
51- 62 A12 --- FileName Name of the table with effective heights
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Byte-by-byte Description of file: sun.dat [agpt]*.dat
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Bytes Format Units Label Explanations
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4- 10 F7.4 um lambda Central Wavelength
15- 21 F7.4 km Effhei Effective height
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Acknowledgements:
Fabian Wunderlich, fabian.wunderlich(at)tu-berlin.de
(End) Fabian Wunderlich [TU Berlin, Germany], Patricia Vannier [CDS] 27-Feb-2019