J/AJ/159/18 Jovian-type planets around M dwarfs with MIRI/JWST (Brande+, 2020)
The feasibility of directly imaging nearby cold Jovian planets with MIRI/JWST.
Brande J., Barclay T., Schlieder J.E., Lopez E.D., Quintana E.V.
<Astron. J., 159, 18 (2020)>
=2020AJ....159...18B 2020AJ....159...18B (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets ; Stars, nearby ; Stars, dwarfs ; Stars, M-type ;
Infrared sources ; Models
Keywords: Direct imaging - M stars - Solar neighborhood -
Extrasolar gas giants - Exoplanets - Infrared astronomy
Abstract:
The upcoming launch of the James Webb Space Telescope (JWST) will
dramatically increase our understanding of exoplanets, particularly
through direct imaging. Microlensing and radial velocity surveys indicate
that some M dwarfs host long-period giant planets. Some of these planets
will likely be just a few parsecs away and a few astronomical units from
their host stars, a parameter space that cannot be probed by existing
high-contrast imagers. We studied whether the coronagraphs on the
Mid-infrared Instrument on JWST can detect Jovian-type planets around
nearby M dwarfs. For a sample of 27 very nearby M dwarfs, we simulated
a sample of Saturn-Jupiter-mass planets with three atmospheric
configurations and three orbital separations, observed in three different
filters. We found that the f1550c 15.5 µm filter is best suited for
detecting Jupiter-like planets. Jupiter-like planets with patchy cloud
cover, 2 au from their star, are detectable at 15.5 µm around 14 stars
in our sample, while Jupiters with clearer atmospheres are detectable
around all stars in the sample. Saturns were most detectable at 10.65
and 11.4 µm (f1065c and f1140c filters), but only with cloud-free
atmospheres and within 3 pc (six stars). Surveying all 27 stars would
take <170 hr of JWST integration time, or just a few hours for a shorter
survey of the most favorable targets. There is one potentially detectable
known planet in our sample: GJ 832 b. Observations aimed at detecting
this planet should occur in 2024-2026, when the planet is maximally
separated from the star.
Description:
The Mid-infrared Instrument (MIRI) instrument on JWST covers 4.9-28.8 µm
(see Figure 2 and Rieke et al. 2015PASP..127..584R 2015PASP..127..584R), which is well suited
to our parameter space of interest. MIRI has four coronagraphs: three are
four-quadrant phase masks optimized for use at 10.65, 11.4, and 15.5 µm
and have small inner working angles (IWAs) of 0.33", 0.36", and 0.49"
(equal to the 1 λ/D limit), respectively.
We selected a population of stars from the RECONS list of the 100 nearest
star systems to Earth. Of the nearest M dwarf stellar systems, we excluded
those in tight binaries due to the observational and dynamical
complications that would produce. We selected 27 stars in the RECONS list
that fit our criteria.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 66 27 Stellar targets used as simulated exoplanet
hosts
table4.dat 68 17496 Planet S/N at maximum star exposure (6.24 hr),
for planets placed around Proxima Centauri
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See also:
J/MNRAS/407/2269 : Polarisation of a sample of late M dwarfs (Morin+, 2010)
J/AJ/147/94 : Solar neighborhood. XXXII. L and M dwarfs (Dieterich+, 2014)
J/ApJ/807/45 : Potentially habitable planets orbiting M dwarfs
(Dressing+, 2015)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Star Host star
13- 17 A5 --- SpType Spectral type
19- 22 I4 K Temp [2040/3722] Temperature
23 A1 --- n_Temp [a] Note on Temp (1)
25- 30 F6.3 mag Vmag [7.34/18.69] V band magnitude
32- 37 F6.3 mag Jmag [4.2/10.725] J band magnitude
39- 43 F5.3 Msun Mass [0.07/0.5] Stellar mass
45- 49 F5.3 Rsun Rad [0.1/0.492] Stellar radius
50 A1 --- n_Rad [a] Note on Rad (1)
52- 55 F4.2 pc Dist [1.29/6.4] Distance
57- 66 A10 --- Ref References (2)
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Note (1): Note as follows:
a = Assumed value based on available stellar properties.
Note (2): Reference as follows:
1 = SIMBAD (Wenger et al. 2000A&AS..143....9W 2000A&AS..143....9W);
2 = NASA Exoplanet Archive (Akeson et al. 2013PASP..125..989A 2013PASP..125..989A);
3 = Research Consortium on Nearby Stars (http://www.recons.org);
4 = Bobylev (2010AstL...36..220B 2010AstL...36..220B);
5 = Demory et al. (2009A&A...505..205D 2009A&A...505..205D);
6 = Dawson & De Robertis (2004AJ....127.2909D 2004AJ....127.2909D);
7 = Doyle & Butler (1990A&A...235..335D 1990A&A...235..335D);
8 = Johnson & Wright (1983ApJS...53..643J 1983ApJS...53..643J);
9 = Morin et al. (2010, J/MNRAS/407/2269);
10 = Lacy (1977ApJS...34..479L 1977ApJS...34..479L);
11 = Davison et al. (2015AJ....149..106D 2015AJ....149..106D);
12 = Dieterich et al. (2014, J/AJ/147/94);
13 = Pasinetti Fracassini et al. (2001A&A...367..521P 2001A&A...367..521P);
14 = Berger et al. (2006ApJ...644..475B 2006ApJ...644..475B);
15 = von Braun et al. (2014MNRAS.438.2413V 2014MNRAS.438.2413V);
16 = Henry et al. (2006AJ....132.2360H 2006AJ....132.2360H);
17 = Reiners et al. (2009ApJ...692..538R 2009ApJ...692..538R);
18 = Linsky et al. (1995ApJ...455..670L 1995ApJ...455..670L).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Star Host star
13- 18 A6 --- Filter MIRI coronagraphic filter (1)
20- 26 A7 --- Planet Planet used as simulated exo-target
28- 40 A13 --- Atmo Atmospheric configuration, cloud cover
42 I1 AU SMA [1/5] Orbit semimajor axis
44- 47 F4.2 arcsec Sep1 [0.16/3.88] Angular separation
49- 53 F5.2 --- Sep2 [0.32/11.75] Angular separation (2)
55- 60 F6.2 --- S/N [0/453.29] Signal-to-noise ratio for observation
62- 68 F7.1 s ExpTime [898.8/22470] JWST total exposure time
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Note (1): MIRI coronagraphic filter as follows:
f1065c = 10.65 µm;
f1140c = 11.4 µm;
f1550c = 15.5 µm.
Note (2): In multiples of the inner working angle, λ/D.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 21-Feb-2020