J/ApJ/779/188 Spectra of nearby late K and M Kepler stars (Mann+, 2013)
Spectro-thermometry of M dwarfs and their candidate planets: too hot, too cool,
or just right?
Mann A.W., Gaidos E., Ansdell M.
<Astrophys. J., 779, 188 (2013)>
=2013ApJ...779..188M 2013ApJ...779..188M
ADC_Keywords: Planets ; Stars, late-type ; Stars, diameters ; Stars, masses ;
Spectra, infrared
Keywords: astrobiology - planetary systems - stars: fundamental parameters -
stars: late-type
Abstract:
We use moderate-resolution spectra of nearby late K and M dwarf stars
with parallaxes and interferometrically determined radii to refine
their effective temperatures, luminosities, and metallicities. We use
these revised values to calibrate spectroscopic techniques to infer
the fundamental parameters of more distant late-type dwarf stars. We
demonstrate that, after masking out poorly modeled regions, the newest
version of the PHOENIX atmosphere models accurately reproduce
temperatures derived bolometrically. We apply methods to late-type
hosts of transiting planet candidates in the Kepler field, and
calculate effective temperature, radius, mass, and luminosity with
typical errors of 57K, 7%, 11%, and 13%, respectively. We find
systematic offsets between our values and those from previous analyses
of the same stars, which we attribute to differences in atmospheric
models utilized for each study. We investigate which of the planets in
this sample are likely to orbit in the circumstellar habitable zone.
We determine that four candidate planets (KOI 854.01, 1298.02,
1686.01, and 2992.01) are inside of or within 1σ of a
conservative definition of the habitable zone, but that several
planets identified by previous analyses are not (e.g., KOI 1422.02 and
KOI 2626.01). Only one of the four habitable-zone planets is Earth
sized, suggesting a downward revision in the occurrence of such
planets around M dwarfs. These findings highlight the importance of
measuring accurate stellar parameters when deriving parameters of
their orbiting planets.
Description:
Optical spectra of both the calibration sample and the Kepler planet
host sample were obtained with the SuperNova Integral Field
Spectrograph (SNIFS) on the University of Hawaii 2.2m telescope on top
Mauna Kea. The spectral resolution, R, is ∼800 in the blue channel
(3200-5200Å) and ∼1000 in the red (5100-9700Å).
We obtained NIR spectra of our Boyajian+, 2012 (J/ApJ/757/112)
calibration sample and selected Kepler stars with candidate habitable
zone (HZ) planets (see Section 7) using the SpeX spectrograph attached
to the NASA Infrared Telescope Facility (IRTF) on Mauna Kea (0.8-2.4um
range at a resolution of R∼2000).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 66 123 Late-type Kepler planet host parameters
table4.dat 51 188 Kepler planet parameters
hzc/* . 4 *Habitable zone candidates spectra in FITS format
koi/* . 119 *KOIs spectra in FITS format
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Note on hzc/* and koi/* directories: The data includes both the SNIFS and SpeX
data, as well as BT-SETTL models to fill in the gaps. The habitable zone
candidates are not absolutely flux calibrated. Data based on BT-SETTL models
have errors set to 0. The KOIs contain only SNIFS data (optical).
The three columns of the array in .fits files are:
COLUMN1 = Wavelength [microns]
COLUMN2 = Flux [erg/s/cm2/Å=cW/m2/nm]
COLUMN3 = Error [erg/s/cm2/Å=cW/m2/nm]
See Sections 3 and 4 for more information.
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/A+A/556/A15 : Effective temperature scale of M dwarfs (Rajpurohit+, 2013)
J/ApJ/771/107 : Spectroscopy of faint KOI stars (Everett+, 2013)
J/ApJ/770/90 : Candidate planets in the habitable zones (Gaidos, 2013)
J/ApJ/770/43 : Spectroscopic [Fe/H] of Kepler stars (Mann+, 2013)
J/ApJ/767/95 : Improved parameters of smallest KIC stars (Dressing+, 2013)
J/AJ/145/102 : Spectroscopy of M dwarfs in the northern sky (Lepine+, 2013)
J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)
J/AJ/145/52 : Late K & M dwarf abundances in binary systems (Mann+, 2013)
J/A+A/549/A109 : HARPS XXXI. The M-dwarf sample (Bonfils+, 2013)
J/A+A/549/A8 : Extinction properties above Mauna Kea (Buton+, 2013)
J/ApJ/757/112 : Stellar diameters. II. K and M-stars (Boyajian+, 2012)
J/ApJ/753/90 : Stellar param. of K5 and later type Kepler stars (Mann+, 2012)
J/ApJ/750/L37 : Stellar parameters of low-mass KOIs (Muirhead+, 2012)
J/ApJ/748/93 : K-band spectra for 133 nearby M dwarfs (Rojas-Ayala+, 2012)
J/ApJ/746/36 : RV standard deviation in the M2K survey (Gaidos+, 2012)
J/AJ/142/112 : KIC photometric calibration (Brown+, 2011)
J/ApJ/736/19 : Kepler planetary candidates. II. (Borucki+, 2011)
J/MNRAS/403/1949 : UBV(RcIc)JHK photometry of HIP nearby stars (Koen+, 2010)
J/AJ/128/463 : A preliminary 20pc census from the NLTT catalog (Reid+, 2004)
J/A+A/275/101 : Chemical evolution of the galactic disk I. (Edvardsson+ 1993)
J/AJ/105/1962 : K and M stars photometry (Weis, 1993)
http://archive.stsci.edu/kepler : Kepler MAST home page
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- KOI [227/3144] Kepler Object of Interest Number
6 A1 --- f_KOI [b-hz] Individual notes (1)
9- 16 I8 --- KIC Kepler Input Catalog ID (V/133)
19- 22 I4 K Teff [3157/5085] Effective temperature (2)
25- 29 F5.3 Rsun R* [0.18/0.94] Stellar radius
32- 36 F5.3 Rsun e_R* [0.03/0.08]? Error on R*
39- 43 F5.3 Msun M* [0.14/0.9] Stellar mass
46- 50 F5.3 Msun e_M* [0.05/0.3]? Error on M*
54- 58 F5.3 Lsun L* [0.003/0.42] Stellar luminosity
62- 66 F5.3 Lsun e_L* [0.003/0.04]? Error on L*
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Note (1): Flag as follows:
b = Consistent with Teff=3820±90K, R*=0.55±0.11
and M*=0.59±0.06 reported by Johnson et al. (2012AJ....143..111J 2012AJ....143..111J).
c = Consistent with R*=0.54±0.05, M*=0.57±0.05 reported
by Pineda et al. (2013ApJ...767...28P 2013ApJ...767...28P).
d = KOI 940 and KOI 2704 have Teff values outside our grid of calibration
stars.
e = Kepler-32. Consistent with Teff=3793+80-74, R*=0.53±0.02,
M*=0.54±0.02 reported by Swift et al. (2013ApJ...764..105S 2013ApJ...764..105S).
f = Kepler-42. Consistent with Teff=3068±174, R*=0.17±0.04,
M*=0.13±0.05 reported by Muirhead et al. (2012ApJ...747..144M 2012ApJ...747..144M).
g = Kepler-61. Slightly warmer than, but consistent with
Teff=4017+68-150, R*=0.62+0.02-0.05, and
M*=0.635±0.037 reported by Ballard et al. (2013ApJ...773...98B 2013ApJ...773...98B).
h = KOI 2704 has a Teff cooler than our grid of calibration stars. We
conservatively assign upper limits to this star based on the
calibration star with the best matched temperature (GJ 699).
z = Star has Habitable Zone candidate; flag added by CDS.
Note (2): Error on Teff is assumed to be 58K for all stars in the sample.
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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- 8 F8.2 --- KOI [227.01/3144.01] Kepler Object of Interest Number
9 A1 --- f_KOI [a] Upper limits only (1)
11- 18 I8 --- KIC Kepler Input Catalog ID (V/133)
21- 26 F6.3 Rgeo Rp [0.5/20.5] Planet Radius
29- 34 F6.3 Rgeo e_Rp [0.05/0.6]? Error in Rp
37- 43 F7.3 Earth S [0.2/605] Planet irradiance; relative to Earth
46- 51 F6.3 Earth e_S [0.03/79]? Error in S
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Note (1):
a = KOI 2704 has a Teff below our coolest calibration star. Therefore
only upper limits are given.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 07-May-2015