J/AJ/158/38 New substellar discoveries from Kepler and K2 (Carmichael+, 2019)
New substellar discoveries from Kepler and K2: is there a brown dwarf desert?
Carmichael T.W., Latham D.W., Vanderburg A.M.
<Astron. J., 158, 38 (2019)>
=2019AJ....158...38C 2019AJ....158...38C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, brown dwarf ; Radial velocities ; Stars, masses ;
Stars, diameters ; Effective temperatures ; Abundances, [Fe/H] ;
Photometry ; Exoplanets
Keywords: brown dwarfs - techniques: photometric -
techniques: radial velocities - techniques: spectroscopic
Abstract:
We present the discoveries of a brown dwarf (BD) and a low-mass star from
the Kepler and K2 missions. The newly discovered BD is EPIC 212036875b
and the low-mass star is KOI-607b. EPIC 212036875b has a mass of
Mb=52.3±1.9 MJ, a radius of Rb=0.874±0.017 RJ, and orbits its
host star in P=5.169885±0.000027 days. Its host star is a late F-type
star with M*=1.288±0.065 M☉, R*= 1.498±0.025 R☉, and
Teff=6238±60 K. KOI-607b has a mass of Mb=95.1±3.4 MJ, a radius
of Rb=1.089±0.089 RJ, and an orbital period of
P=5.89399148±0.00000060 days. The primary star in the KOI-607 system is
a G dwarf with M*=0.993±0.052 M☉, R*= 0.915±0.031 R☉,
and Teff=5418±87 K. We also revisit a BD, CWW 89Ab, that was previously
published by Nowak et al. 2017AJ....153..131N 2017AJ....153..131N (under the designation
EPIC 219388192b). CWW 89Ab is one of two known transiting BDs associated
with a star cluster, which illustrates the need for more BDs with accurate
masses, radii, and reliable age determinations to test theoretical models.
We find that the newly discovered BD, EPIC 212036875b, falls in the middle
of the so-called BD desert, indicating that EPIC 212036875b is either
a particularly rare object, or the BD desert may not be so dry after all.
Description:
The spectra for KOI-607, EP212, and CWW 89A were taken with the Tillinghast
Reflector Echelle Spectrograph (TRES) instrument on Mt. Hopkins, Arizona.
The spectrograph has a resolution of R=44000 and covers wavelengths from
390 to 910 nm. CWW 89A has 18 TRES spectra that were taken in 2015 and
2016 with exposure times ranging from 1200 to 1700 s and a signal-to-noise
(S/N) per resolution element ranging from 22 to 34 (except for one point
near phase 0.86, which has an exposure time of 400 s and an S/N of 6.8;
this spectrum is not used to derive stellar parameters). EP212 has 14 TRES
spectra taken in 2018 with exposure times ranging from 400 to 1800 s and
an S/N ranging from 22 to 45. KOI-607 also has 14 TRES spectra and these
were taken in 2014 (except for one point at phase 0.80 that was taken
in 2018) with exposure times ranging from 1800 to 3600 s and an S/N ranging
from 13 to 17.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table7.dat 136 23 List of published transiting brown dwarfs
as of March 2019
table8.dat 97 22 Additional information on published transiting
brown dwarfs
table2.dat 27 18 Multi-order relative radial velocities
of CWW 89A from TRES
table3.dat 27 14 Multi-order relative radial velocity
measurements of EPIC 212036875 from TRES
table4.dat 27 14 Multi-order relative radial velocity
measurements of KOI-607 from TRES
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJ/683/1076 : Transits of exoplanet XO-3b (Winn+, 2008)
J/ApJ/718/1353 : Light curve of the triple system NLTT 41135 (Irwin+, 2010)
J/ApJ/761/123 : KELT-1 photometry and spectroscopy follow-up (Siverd+, 2012)
J/AJ/153/15 : Photometry and spectroscopy of EPIC 201702477 (Bayliss+, 2017)
J/A+A/628/A64 : EPIC 212036875b griz light curves (Persson+, 2019)
J/AJ/157/31 : Differential photometry & radial velocities of HATS-70
(Zhou+, 2019)
Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name System identifier
15 A1 --- m_Name [abc] Multiplicity index on Name
17 A1 --- Flag1 [abcdefg] Flag on Name (G1)
19- 25 F7.3 d Per [1.218/166.788] Orbital period
27- 31 F5.2 Mjup Mass [11.79/95.1] Brown dwarf mass
33- 36 F4.2 Mjup e_Mass [0.59/6.8] Uncertainty in Mass
38- 42 F5.3 Rjup R [0.757/6.5] Brown dwarf radius
44- 48 F5.3 Rjup e_R [0.015/0.53] Uncertainty in R
50 A1 --- l_e Limit flag on e
51- 56 F6.4 --- e [0/0.689] Eccentricity
58 A1 --- f_e [a] Flag indicating an adopted value on e
60- 65 F6.4 --- e_e [0.0002/0.057]? Uncertainty in e
67- 71 F5.3 Msun Mp* [0.188/1.78]? Primary stellar mass
73- 76 F4.2 Msun Ms* [0.3]? Secondary stellar mass
78- 82 F5.3 Msun e_Mp* [0.015/0.12]? Uncertainty in Mp*
84- 88 F5.3 Rsun Rp* [0.21/1.881]? Primary stellar radius
90- 94 F5.3 Rsun e_Rp* [0.005/0.31]? Uncertainty in Rp*
96- 99 I4 K Teff [3100/7930]? Stellar effective temperature
101-103 I3 K e_Teff [40/820]? Uncertainty in Teff
105-110 F6.3 [Sun] [Fe/H] [-0.24/0.44]? Metallicity
112-116 F5.3 [Sun] e_[Fe/H] [0.053/0.25]? Uncertainty in [Fe/H]
118-136 A19 --- Bibcode1 Bibcode of reference
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Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name System identifier
16 A1 --- Flag2 [bcd] Flag on Name (G1)
18- 19 I2 h RAh ? Hour of Right Ascension (J2000)
21- 22 I2 min RAm ? Minute of Right Ascension (J2000)
24- 28 F5.2 s RAs ? Second of Right Ascension (J2000)
30 A1 --- DE- Sign of the Declination (J2000)
31- 32 I2 deg DEd ? Degree of Declination (J2000)
34- 35 I2 arcmin DEm ? Arcminute of Declination (J2000)
37- 41 F5.2 arcsec DEs ? Arcsecond of Declination (J2000)
43- 47 F5.2 mag Vmag [9.8/18.73]? V band magnitude
49- 53 F5.2 mag Gmag [14.35/18.94]? G-band magnitude from the Gaia
mission (Cat. I/345)
55- 77 A23 --- Ref Reference
79- 97 A19 --- Bibcode2 Bibcode of the reference
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Byte-by-byte Description of file: table2.dat table3.dat table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.6 d BJD [6799.92/8430.98] Barycentric Julian Date
(BJD-2450000)
13- 20 F8.2 m/s RV [-8260.62/11493.66] Radial velocity
22- 27 F6.2 m/s e_RV [35.97/389.48] Uncertainty in RV
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Global notes:
Note (G1): Flag as follows:
a = LHS 6343 is a triple system with two M-dwarfs and one brown dwarf;
b = XO-3b is most likely a high mass gas giant exoplanet rather than a brown
dwarf;
c = KOI-189b is either a high mass brown dwarf or a very low mass star as its
mass is near the substellar upper mass limit of 80 MJ;
d = KOI-607b is a low mass star and not a brown dwarf;
e = AD 3116b is a transiting brown dwarf associated with the Praesepe open
cluster;
f = RIK 72b is in the Upper Scorpius OB association;
g = 2M0535-05 is a brown dwarf binary.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 09-Sep-2019