J/AJ/160/19 827 ultracool dwarfs with K2 (Sagear+, 2020)
Upper limits on planet occurrence around ultracool dwarfs with K2.
Sagear S.A., Skinner J.N., Muirhead P.S.
<Astron. J., 160, 19 (2020)>
=2020AJ....160...19S 2020AJ....160...19S
ADC_Keywords: Stars, dwarfs; Stars, L-type; Stars, M-type; Spectra, infrared;
Photometry, infrared; Spectral types; Optical
Keywords: M dwarf stars ; L dwarfs ; Exoplanets ; Transits ;
Late-type dwarf stars ; Transit photometry ; Space telescopes
Abstract:
The occurrence of planets orbiting ultracool dwarfs is poorly
constrained. We present results from a guest observer program on
NASA's K2 spacecraft to search for transiting planets orbiting a
sample of 827 ultracool dwarfs. Having found no transiting planets in
our sample, we determined an upper limit on the occurrence of planets.
We simulated planets orbiting our sample for a range of orbital
periods and sizes. For the simulated planets that transit their host,
we injected the transit light curve into the real K2 light curves,
then attempted to recover the injected planets. For a given occurrence
rate, we calculated the probability of seeing no planets, and use the
results to place an upper limit on planet occurrence as a function of
planet radius and orbital period. We find that short-period,
mini-Neptune and Jupiter-sized planets are rare around ultracool
dwarfs, consistent with results for early and mid-type M dwarf stars.
We constrain the occurrence rate η for planets between 0.5 and 10
R{earth} with orbital periods between 1 and 26.3days.
Description:
To identify ultracool dwarfs in the K2 fields, we searched the Baryon
Oscillation Sky Survey (BOSS) Ultracool Dwarf catalog
(BUD; Schmidt+, 2015, J/AJ/149/158). In total, we identified 827
late-type M dwarfs and early-type L dwarfs bright enough to be
observed as a part of K2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 70 827 K2 ultracool dwarf sample
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)
J/AJ/133/2258 : Activity & kinematics ultracool dwarfs (Schmidt+, 2007)
J/AJ/136/1290 : Ultracool dwarfs from the 2MASS (Reid+, 2008)
J/A+A/497/619 : New ultra-cool dwarfs from SDSS and 2MASS (Zhang+, 2009)
J/MNRAS/404/1817 : 2MASS/SDSS data for 806 ultracool dwarfs (Zhang+, 2010)
J/ApJS/201/19 : Hawaii Infrared Parallax Program. I. (Dupuy+, 2012)
J/A+A/565/A21 : Astrometry around ultracool dwarfs (Lazorenko+, 2014)
J/MNRAS/443/2561 : CONCH-SHELL catalog of nearby M dwarfs (Gaidos+, 2014)
J/ApJ/807/45 : Habitable planets orbiting M dwarfs (Dressing+, 2015)
J/ApJ/814/130 : Planet occur. rates calculated for KOIs (Mulders+, 2015)
J/AJ/149/158 : The BUD sample I. Ldwarf activity sample (Schmidt+,2015)
J/MNRAS/449/3966 : Ultracool white dwarfs (Gianninas+, 2015)
J/ApJS/224/2 : K2 EPIC stellar properties 138600 targets (Huber+, 2016)
J/ApJ/817/112 : NEOWISE/AllWISE high PM objects (Schneider+, 2016)
J/A+A/589/A49 : Photometric brown-dwarf classification (Skrzypek+, 2016)
J/A+A/598/A92 : New ultracool subdwarfs (Lodieu+, 2017)
J/A+A/619/L8 : Ultra-cool dwarfs candidates in Gaia DR2 (Reyle, 2018)
J/ApJ/858/55 : K2 ultracool dwarfs III. M6-L0 flares (Paudel+, 2018)
J/AJ/158/75 : M dwarfs planet occurrence (Hardegree-Ullman+, 2019)
J/AJ/157/231 : MLSDSS-GaiaDR2 sample of M and L dwarfs (Kiman+, 2019)
J/A+A/641/A170 : Ultracool dwarf K2 light curves (Sestovic+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- EPIC [201453319/251812062] EPIC identification
11- 19 F9.5 deg RAdeg [67.5/359] Right Ascension (J2000)
21- 29 F9.5 deg DEdeg [-27.7/26.2] Declination (J2000)
31- 35 F5.2 mag Kpmag [11.59/24.89] Magnitude apparent in Kepler filter
37- 40 A4 --- SpT Spectral Type
42- 48 A7 --- Camp K2 Campaign(s)
50- 68 A19 --- Gaia Gaia Source identification
70- 70 A1 --- f_SpT Spectral Type source (1)
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Note (1): Sources as follows:
s = spectrum (781 occurrences)
p = photometry (46 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 02-Oct-2020