J/ApJS/239/5 Variable stars and cand. planets from K2 (Crossfield+, 2018)
A TESS dress rehearsal: planetary candidates and variables from K2 Campaign 17.
Crossfield I.J.M., Guerrero N., David T., Quinn S.N., Feinstein A.D.,
Huang C., Yu L., Collins K.A., Fulton B.J., Benneke B., Peterson M.,
Bieryla A., Schlieder J.E., Kosiarek M.R., Bristow M., Newton E., Bedell M.,
Latham D.W., Christiansen J.L., Esquerdo G.A., Berlind P., Calkins M.L.,
Shporer A., Burt J., Ballard S., Rodriguez J.E., Mehrle N., Dressing C.D.,
Livingston J.H., Petigura E.A., Seager S., Dittmann J., Berardo D., Sha L.,
Essack Z., Zhan Z., Owens M., Kain I., Isaacson H., Ciardi D.R.,
Gonzales E.J., Howard A.W., de Miranda Cardoso J.V.
<Astrophys. J. Suppl. Ser., 239, 5 (2018)>
=2018ApJS..239....5C 2018ApJS..239....5C
ADC_Keywords: Binaries, eclipsing; Stars, variable; Exoplanets; Photometry;
Effective temperatures; Stars, diameters; Rotational velocities
Keywords: methods: data analysis ; planets and satellites: detection ;
techniques: photometric
Abstract:
We produce light curves for all ∼34000 targets observed with K2 in
Campaign 17 (C17), identifying 34 planet candidates, 184 eclipsing
binaries, and 222 other periodic variables. The forward-facing
direction of the C17 field means follow-up can begin immediately now
that the campaign has concluded and interesting targets have been
identified. The C17 field has a large overlap with C6, so this latest
campaign also offers an infrequent opportunity to study a large number
of targets already observed in a previous K2 campaign. The timing of
the C17 data release, shortly before science operations begin with the
Transiting Exoplanet Survey Satellite (TESS), also lets us exercise
some of the tools and methods developed for identification and
dissemination of planet candidates from TESS. We find excellent
agreement between these results and those identified using only
K2-based tools. Among our planet candidates are several planet
candidates with sizes <4R⊕ and orbiting stars with Kp≲10
(indicating good RV targets of the sort TESS hopes to find) and a
Jupiter-sized single-transit event around a star already hosting a
6 day planet candidate.
Description:
Launched in 2009, the success of Kepler and its extended mission, K2,
is unprecedented. Unlike the original Kepler mission, K2 observes
along the ecliptic plane.
K2 observed Campaign 17 (C17) from March 1 until 2018 May 8. We
followed exactly the methods of Yu+ (2018, J/AJ/156/22) to compute
photometry and identify transit-like threshold-crossing events (TCEs).
The recently launched Transiting Exoplanet Survey Satellite (TESS)
will observe ∼90% of the sky, approximately 400 times what Kepler
observed and 26 times what K2 has observed so far.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 105 47 *Stellar parameters
table2.dat 208 34 Planet candidates from Campaign 17 (C17)
table3.dat 117 184 Eclipsing binaries
table4.dat 45 222 Other periodic variables
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Note on table1.dat: Keck/HIRES data and analysis described by
Petigura+ (2018, J/AJ/155/21); IRTF/SpeX data and analysis by
Dressing+ (2017, J/ApJ/836/167). Numerous spectra have also been
acquired with the Tillinghast Reflector Echelle Spectrograph (TRES)
and uploaded to the ExoFOP-K2 website (https://exofop.ipac.caltech.edu/k2/).
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
VII/250 : The 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003)
J/ApJS/141/503 : Radial Velocities for 889 late-type stars (Nidever+, 2002)
J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)
J/ApJ/809/25 : Stellar and planet properties for K2 candidates (Montet+, 2015)
J/ApJ/809/77 : Transiting Exoplanet Survey Satellite (TESS) (Sullivan+, 2015)
J/ApJS/226/7 : Planet cand. discovered using K2's 1st yr (Crossfield+, 2016)
J/ApJS/224/2 : K2 EPIC stellar properties for 138600 targets (Huber+, 2016)
J/AJ/152/114 : Pleiades members with K2 light curves. II. (Rebull+, 2016)
J/A+A/587/A64 : Physical properties of giant exoplanets (Santerne+, 2016)
J/ApJS/222/14 : Planetary candidates from 1st yr K2 mission (Vanderburg+, 2016)
J/ApJ/836/167 : K2 planetary syst. around low-mass stars. I. (Dressing+, 2017)
J/AJ/154/207 : K2 planetary systems orbiting low-mass stars (Dressing+, 2017)
J/AJ/154/109 : California-Kepler Survey (CKS). III. Radii (Fulton+, 2017)
J/AJ/155/136 : Planets around bright stars in K2 campaigns 0-10 (Mayo+, 2018)
J/AJ/155/21 : Planet candidates from K2 campaigns 5-8 (Petigura+, 2018)
J/AJ/155/196 : K2 LCs for members of USco & ρ Oph (Rebull+, 2018)
J/AJ/156/22 : Planetary candidates from K2 Campaign 16 (Yu+, 2018)
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 [212428509/251554286] EPIC number
11 A1 --- f_EPIC [gi] Flag on EPIC (1)
13- 16 F4.1 mag Kpmag [9.7/14.8] Kepler magnitude
18- 31 F14.6 d BJD ? UTC Barycentric Julian Date
of TRES observation
33- 36 F4.1 --- S/N [15.1/54.1]? TRES signal-to-noise ratio (2)
38- 41 I4 K Teff [4635/6105]? TRES effective temperature
43- 46 F4.2 [cm/s2] logg [3.2/4.7]? TRES log of surface gravity
48- 52 F5.2 [-] [M/H] [-0.5/0.5]? TRES metallicity
54- 57 F4.1 km/s vsini [0.8/12]? TRES rotational velocity (3)
59- 65 F7.3 km/s RV [-46.7/29.6]? TRES radial velocity (4)
67- 70 I4 K TeffH [4226/6102]? HIRES effective temperature
71- 73 A3 --- f_TeffH Flag on TeffH (1)
75- 78 F4.2 [cm/s2] loggH [3.3/4.7]? HIRES log of surface gravity
79 A1 --- f_loggH Flag on loggH (1)
81- 85 F5.2 [-] [Fe/H]H [-0.5/0.4]? HIRES metallicity
86 A1 --- f_[Fe/H]H Flag on [Fe/H]H (1)
88- 91 F4.1 km/s vsiniH [1.1/10]? HIRES rotational velocity
93- 95 A3 --- SpT SpeX MK spectral type
97-100 I4 K TeffS [3412/4972]? SpeX effective temperature
102-105 F4.2 [cm/s2] loggS [4.5/4.9]? SpeX log of surface gravity
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Note (1): Flag as follows:
g = Star too cool for SpecMatch analysis (see Petigura+ 2018, J/AJ/155/21).
h = Star observed with APF instead of HIRES, but stellar parameters inferred
using the same approach as described in Petigura+ (2018, J/AJ/155/21).
i = Multi-lined spectrum.
Note (2): Signal-to-noise ratio per resolution element in the wavelength range
5060-5315Å.
Note (3): SPC measures the broadening from an edge-on rotator with a fixed
macroturbulent velocity of 1km/s. Different values of macroturbulence
may bias this value for slow rotators. As such, we caution against
interpreting this value as vsini without further analysis.
Note (4): The RVs reported here have been shifted onto the IAU scale using
standard star velocities, on which, e.g., HD 182488, has an absolute
RV of -21.508 (Nidever+ 2002, J/ApJS/141/503). The uncertainties of
the reconnaissance RVs on the TRES native system are typically on
the order of 50m/s (also affected by Teff, S/N and vsini), though the
offset to the absolute scale carries similar uncertainty.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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2- 10 I9 --- EPIC EPIC number
11 A1 --- --- [.]
12- 13 I02 --- Pl Candidate planet number
15- 20 F6.3 mag Kpmag [9.7/17] Kp magnitude
22- 31 F10.7 d Per [0.5/28.5] Orbital period
33- 41 F9.7 d E_Per [2.7e-06/0.004] Upper uncertainty in Per
43- 51 F9.7 d e_Per [2.7e-06/0.004] Lower uncertainty in Per
53- 62 F10.5 d T0 Epoch T0, TDB Barycentric Julian Date BJD-2454833
64- 70 F7.5 d E_T0 [0.0001/0.006] Upper uncertainty in T0
72- 78 F7.5 d e_T0 [0.0001/0.007] Lower uncertainty in T0
80- 85 F6.3 h T14 [0.7/11] Transit duration, T14 time
87- 91 F5.3 h E_T14 [0.02/3.3] Upper uncertainty in T14
93- 97 F5.3 h e_T14 [0.02/6.1] Lower uncertainty in T14
99-104 F6.3 % Rp/R* [1.8/45.4] Ratio Planet to Star radius, Rp/R*
106-111 F6.3 % E_Rp/R* [0.07/11] Upper uncertainty in Rp/R*
113-117 F5.3 % e_Rp/R* [0.04/8.1] Lower uncertainty in Rp/R*
119-122 F4.2 Rsun R* [0.3/2.6] Stellar Radius
124-127 I4 K Teff [3585/6560] Surface Temperature, star
129-134 F6.3 Rgeo Rp [1.4/26] Planet Radius
136-141 F6.3 Rgeo E_Rp [0.08/15.4] Upper uncertainty in Rp
143-147 F5.3 Rgeo e_Rp [0.09/5.1] Lower uncertainty in Rp
149-155 F7.1 Earth Sinc [25.4/10946] Incident irradiation
157-208 A52 --- Notes Notes
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- EPIC [212406350/251810686] Star EPIC ID
11- 16 F6.3 mag Kpmag [8.9/19.5] Kp magnitude
18- 30 F13.5 d Epoch Epoch, Barycentric Julian Date, TDB
32- 40 F9.6 d Per [0.4/28.3] Orbital Period
42- 49 F8.6 d T14 [0.03/0.7] Transit Duration, T14 time
51- 58 F8.6 % Rc/R* [0.0001/0.8] Ratio Candidate to Star radius,
Rc/R*
60-117 A58 --- Comm Comments
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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- 9 I9 --- EPIC [212404864/251811829] Star EPIC ID
11- 16 F6.3 mag Kpmag [7.9/20.4] Kp magnitude
18- 25 F8.6 d Per [0.1/7.2] Orbital Period
27- 45 A19 --- Comm Comments
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 13-Dec-2018