J/AJ/158/75 Mid-type M dwarfs planet occurrence rates (Hardegree-Ullman+, 2019)
Kepler planet occurrence rates for mid-type M dwarfs as a function of spectral
type.
Hardegree-Ullman K.K., Cushing M.C., Muirhead P.S., Christiansen J.L.
<Astron. J., 158, 75 (2019)>
=2019AJ....158...75H 2019AJ....158...75H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Stars, M-type ; Stars, distances ; Magnitudes ;
Spectral types ; Effective temperatures ; Abundances, [Fe/H] ;
Stars, diameters ; Stars, masses ; Exoplanets
Keywords: planetary systems - stars: fundamental parameters - stars: late-type -
stars : low-mass
Abstract:
Previous studies of planet occurrence rates largely relied on photometric
stellar characterizations. In this paper, we present planet occurrence
rates for mid-type M dwarfs using spectroscopy, parallaxes, and photometry
to determine stellar characteristics. Our spectroscopic observations
have allowed us to constrain spectral type, temperatures, and, in some
cases, metallicities for 337 out of 561 probable mid-type M dwarfs in
the primary Kepler field. We use a random forest classifier to assign
a spectral type to the remaining 224 stars. Combining our data with Gaia
parallaxes, we compute precise (∼3%) stellar radii and masses, which
we use to update planet parameters and occurrence rates for Kepler
mid-type M dwarfs. Within the Kepler field, there are seven M3 V to M5 V
stars that host 13 confirmed planets between 0.5 and 2.5 Earth radii and
at orbital periods between 0.5 and 10 days. For this population, we compute
a planet occurrence rate of 1.19-0.49+0.70 planets per star. For M3 V,
M4 V, and M5 V, we compute planet occurrence rates of 0.86-0.68+1.32,
1.36-1.02+2.30, and 3.07-2.49+5.49 planets per star, respectively.
Description:
In observing semester 2015B, NASA and the NSF implemented Stage 1 of
the Exoplanet Observational Research (NN-EXPLORE) program, enabling
community access to about 100 nights per year on the 3.5 m WIYN telescope
on Kitt Peak at least through commissioning of the extreme precision
Doppler spectrometer NEID (Schwab et al. 2016SPIE.9908E..7HS). We have made
use of the fiber-fed multi-object spectrograph Hydra (Barden et al.
1994SPIE.2198...87B 1994SPIE.2198...87B) on WIYN for this project. We collected spectra over
five observing semesters beginning in 2015 September (NOAO Program IDs
2015B-0280, 2016A-0328, 2016B-0111, 2017A-0185, and 2017B-0095; PI:
K. Hardegree-Ullman). In total, we observed 287 targets with WIYN.
About 90 of our targets have V-band magnitudes fainter than 18.5, which
would require integration times longer than 1 hr using WIYN to achieve
an S/N of 30. We therefore used the DeVeny spectrograph on the 4.3 m
Discovery Channel Telescope (DCT) to observe some of these fainter targets
over four observing runs, collecting spectra of 49 stars.
We used the SpeX spectrograph (Rayner et al. 2003PASP..115..362R 2003PASP..115..362R) on the
NASA Infrared Telescope Facility (IRTF) on Maunakea to observe 82 targets
over 12 partial nights (Program IDs 2016A-981, 2017A-106, and 2017B-021;
PI: K. Hardegree-Ullman). We used SpeX in SXD mode with a 0.3"x15" slit
to obtain 0.8-2.4 µm spectra at R∼2000.
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST;
Cui et al. 2012RAA....12.1197C 2012RAA....12.1197C) is a 4 m class telescope designed to survey
stars and galaxies in the northern hemisphere. Its 4000 fiber multi-object
spectrograph has a wavelength range of 3690-9100 Å at R∼1800. As of
data release 4, over 7.6 million spectra have been gathered in total.
There are LAMOST spectra for 17 of our Kepler targets, including eight
targets we did not observe with WIYN or the DCT. This brings our total
optical spectra count to 327 targets.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 93 327 Stellar parameters for spectroscopically
classified targets
table2.dat 93 220 Stellar parameters for photometrically
classified targets
table3.dat 125 13 Kepler mid-type M dwarf planets
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJ/767/95 : Improved stellar parameters of smallest KIC stars
(Dressing+, 2013)
J/ApJS/211/2 : Revised stellar properties of Q1-16 Kepler targets
(Huber+, 2014)
J/ApJ/814/130 : Planet occurrence rates calculated for KOIs (Mulders+, 2015)
J/ApJ/822/86 : False positive probabilities for Q1-Q17 DR24 KOIs
(Morton+, 2016)
J/MNRAS/457/2877 : Kepler M dwarf stars revised properties (Gaidos+, 2016)
J/ApJS/229/30 : Revised stellar properties of Q1-17 Kepler targets
(Mathur+, 2017)
J/AJ/155/205 : Occurrence rates for Q1-Q16 KOI catalog planet cand.
(Hsu+, 2018)
J/ApJS/235/38 : Kepler planetary cand. VIII. DR25 reliability
(Thompson+, 2018)
Byte-by-byte Description of file: table1.dat table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC [1433760/12884812] Kepler Input Catalog
identifier
10 A1 --- f_KIC Flag on KIC (only in Table 1) (1)
12- 18 F7.3 pc Dist [4.661/848.292]? Distance
20- 26 F7.3 pc e_Dist [0.002/157.725]? Uncertainty in Dist
28- 32 F5.3 mag KsMag [4.064/9.649]? Absolute Ks band magnitude
34- 38 F5.3 mag e_KsMag [0.011/0.847]? Uncertainty in KsMag
40- 44 A5 --- Tel Telescope code (only in Table 1) (2)
46- 50 A5 --- SpType Spectral type
51 A1 --- f_SpType [e] Flag on SpType (only in Table 1) (3)
53- 56 I4 K Teff [2568/3662]?=0 Effective temperature (4)
58- 63 F6.3 [Sun] [Fe/H] [-0.603/0.606]? Metallicity (only in Table 1)
65- 69 F5.3 [Sun] e_[Fe/H] [0.059/0.333]? Uncertainty in [Fe/H] (only
in Table 1)
71- 75 F5.3 Rsun R* [0.119/0.681] Stellar radius
77- 81 F5.3 Rsun e_R* [0.003/0.137] Uncertainty in R*
83- 87 F5.3 Msun M* [0.091/0.654] Stellar mass
89- 93 F5.3 Msun e_M* [0.002/0.126] Uncertainty in M*
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Note (1): Alternative name for KIC as follows:
d = Kepler-1582;
e = Kepler-1649;
f = Kepler-1650;
g = Kepler-1646;
h = Kepler-42;
i = Kepler-446;
j = Kepler-445.
Note (2): Telescope code as follows:
D = Discovery Channel Telescope (DCT);
I = Infrared Telescope Facility (IRTF);
L = Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST);
W = WIYN.
Note (3): Flag as follows:
e = Stars that exhibit Hα emission from a by-eye analysis are classified
with the peculiar flag "e" to denote emission.
Note (4): We adopt a ± 88 K uncertainty for all temperatures from our spectral
type vs. Teff fit (Section 3.3).
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Kepler Kepler planet name
15- 20 A6 --- SpType Host spectral type from this work
22- 26 F5.3 Rsun R* [0.174/0.374]? Stellar radius
28- 32 F5.3 Rsun e_R* [0.005/0.011]? Uncertainty in R*
34- 38 F5.3 Rgeo Rp [0.662/2.39] Planet radius
40- 44 F5.3 Rgeo e_Rp [0.023/0.129] Uncertainty in Rp
46- 50 F5.2 --- a/R* [7.49/45.02] Semi-major axis to stellar radius
ratio
52- 55 F4.2 --- e_a/R* [0.21/1.36] Lower limit uncertainty in a/R*
57- 60 F4.2 --- E_a/R* [0.23/1.42] Upper limit uncertainty in a/R*
62- 71 F10.8 d Per [0.453287/8.68909] Period
73- 78 E6.2 d e_Per [5e-08/8.8e-05] Uncertainty in Per
80- 83 F4.2 h Tdur [0.44/1.75] Transit duration
85- 88 F4.2 h e_Tdur [0.03/0.27] Uncertainty in Tdur
90- 95 F6.4 --- Ptr [0.0231/0.1385] Transit probability
97-102 F6.4 --- e_Ptr [0.0007/0.0041] Uncertainty in Ptr
104-108 F5.2 Earth Sp [1.82/99.78] Insolation flux (in Earth flux)
110-114 F5.2 Earth e_Sp [0.23/11.26] Lower limit uncertainty in Sp
116-120 F5.2 Earth E_Sp [0.25/12.16] Upper limit uncertainty in Sp
122-125 A4 --- Ref Reference(s) (1)
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Note (1): Reference as follows:
1 = Angelo et al. (2017AJ....153..162A 2017AJ....153..162A);
2 = Mann et al. (2017AJ....153..267M 2017AJ....153..267M);
3 = Morton et al. (2016, J/ApJ/822/86);
4 = Muirhead et al. (2015ApJ...801...18M 2015ApJ...801...18M).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 27-Sep-2019