J/AJ/156/78 44 validated planets from K2 Campaign 10 (Livingston+, 2018)
44 validated planets from K2 Campaign 10.
Livingston J.H., Endl M., Dai F., Cochran W.D., Barragan O., Gandolfi D.,
Hirano T., Grziwa S., Smith A.M.S., Albrecht S., Cabrera J., Csizmadia S.,
de Leon J.P., Deeg H., Eigmuller P., Erikson A., Everett M., Fridlund M.,
Fukui A., Guenther E.W., Hatzes A.P., Howell S., Korth J., Narita N.,
Nespral D., Nowak G., Palle E., Patzold M., Persson C.M., Prieto-Arranz J.,
Rauer H., Tamura M., Van Eylen V., Winn J.N.
<Astron. J., 156, 78-78 (2018)>
=2018AJ....156...78L 2018AJ....156...78L (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets ; Stars, double and multiple ; Photometry ;
Stars, diameters ; Stars, masses ; Effective temperatures ;
Abundances, [Fe/H] ; Stars, distances ; Spectroscopy
Keywords: planetary systems - planets and satellites: detection -
techniques: photometric - techniques: spectroscopic
Abstract:
We present 44 validated planets from the 10th observing campaign of
the NASA K2 mission, as well as high-resolution spectroscopy and speckle
imaging follow-up observations. These 44 planets come from an initial
set of 72 vetted candidates, which we subjected to a validation process
incorporating pixel-level analyses, light curve analyses, observational
constraints, and statistical false positive probabilities. Our validated
planet sample has median values of Rp=2.2 R⊕, Porb=6.9 days,
Teq=890 K, and J=11.2 mag. Of particular interest are four ultra-short
period planets (Porb~<1 day), 16 planets smaller than 2 R⊕,
and two planets with large predicted amplitude atmospheric transmission
features orbiting infrared-bright stars. We also present 27 planet
candidates, most of which are likely to be real and worthy of further
observations. Our validated planet sample includes 24 new discoveries
and has enhanced the number of currently known super-Earths
(Rp∼1-2 R⊕), sub-Neptunes (Rp∼2-4 R⊕), and sub-Saturns
(Rp∼4-8 R⊕) orbiting bright stars (J=8-10 mag) by ∼4%, ∼17%,
and ∼11%, respectively.
Description:
In C10, K2 observed a ∼110 square degree field near the North Galactic
cap from 2016 July 06 to 2016 September 20. Long-cadence (30 minute)
exposures of 28345 target stars were downlinked from the spacecraft,
and the data were calibrated and subsequently made available on the
Mikulski Archive for Space Telescopes (http://archive.stsci.edu/k2/; MAST).
We observed candidate host stars with the NASA Exoplanet Star and
Speckle Imager (NESSI) on the 3.5 m WIYN telescope at the Kitt Peak
National Observatory. NESSI is a new instrument that uses high-speed
electron-multiplying CCDs (EMCCDs) to capture sequences of 40 ms
exposures simultaneously in two bands (Scott et al. 2016SPIE.9907E..2RS,
Scott et al. 2018PASP..130e4502S 2018PASP..130e4502S). Data were collected following the
procedures described by Howell et al. (2011, J/AJ/142/19). We conducted
all observations in two bands simultaneously: a "blue" band centered at
562 nm with a width of 44 nm, and a "red" band centered at 832 nm with
a width of 40 nm. We list the individual NESSI data products used in
this work in Table 9.
Most of the high-resolution spectra presented in this paper were obtained
with the Tull Coude cross-dispersed echelle spectrograph (Tull et al.
1995PASP..107..251T 1995PASP..107..251T) at the Harlan J. Smith 2.7 m telescope at McDonald
Observatory. Observations were conducted with the 1.2x8.2" slit, yielding
a resolving power of R∼60000.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 161 63 Stellar parameters
table1.dat 62 72 Candidate planets detected in K2 C10
table4.dat 57 16 *Validated planets with predicted Doppler
semi-amplitudes greater than 1 m/s orbiting
stars brighter than Kp=12 mag
table5.dat 233 72 Planet and candidate parameters
table7.dat 76 72 Individual false positive scenario likelihoods
computed by vespa
table8.dat 22 72 Additional constraints to vespa
table9.dat 28 120 WIYN/NESSI data sets used in this work
table11.dat 27 72 Predicted atmospheric characteristics
table12.dat 107 72 Comparison of parameters between K2 pipelines
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Note on table4.dat: 228721452.01 is not listed here because it does not meet
these criteria, but RV measurements to constrain the mass of 228721452.02
could also reveal the inner planet's mass, as both Keplerian signals would
need to be accounted for in the RV analysis.
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See also:
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
J/AJ/142/19 : Speckle observations of KOI (Howell+, 2011)
J/ApJ/809/25 : Stellar and planet properties for K2 candidates (Montet+, 2015)
J/ApJ/825/19 : Mass-radius relationship for planets with Rp<4
(Wolfgang+, 2016)
J/ApJS/222/14 : Planetary candidates from 1st yr K2 mission (Vanderburg+, 2016)
J/ApJS/226/7 : Planet candidates discovered using K2's 1st yr
(Crossfield+, 2016)
J/AJ/155/21 : Planet candidates from K2 campaigns 5-8 (Petigura+, 2018)
J/AJ/155/136 : Planets orbiting bright stars in K2 campaigns 0-10
(Mayo+, 2018)
J/ApJS/239/5 : Variable stars and cand. planets from K2 (Crossfield+, 2018)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- EPIC EPIC identifier (EPIC NNNNNNNNN)
11- 14 I4 K Teff [3459/8003] Effective temperature
16- 18 I3 K e_Teff [19/454] Lower limit uncertainty in Teff
20- 22 I3 K E_Teff [19/452] Upper limit uncertainty in Teff
24- 27 F4.2 [cm/s2] logg [3.32/4.89] Surface gravity (in cgs units)
29- 32 F4.2 [cm/s2] e_logg [0.01/0.12] Lower limit uncertainty in logg
34- 37 F4.2 [cm/s2] E_logg [0/0.13] Upper limit uncertainty in logg
39- 43 F5.2 [-] [Fe/H] [-0.45/0.38] Metallicity (in dex)
45- 48 F4.2 [-] e_[Fe/H] [0.01/0.23] Lower limit uncertainty in [Fe/H]
50- 53 F4.2 [-] E_[Fe/H] [0.01/0.23] Upper limit uncertainty in [Fe/H]
55- 58 F4.2 Msun Mass [0.38/1.87] Stellar mass
60- 63 F4.2 Msun e_Mass [0.01/0.14] Lower limit uncertainty in Mass
65- 68 F4.2 Msun E_Mass [0.01/0.11] Upper limit uncertainty in Mass
70- 73 F4.2 Rsun Rad [0.37/3.96] Stellar radius
75- 78 F4.2 Rsun e_Rad [0.01/0.16] Lower limit uncertainty in Rad
80- 83 F4.2 Rsun E_Rad [0.01/0.16] Upper limit uncertainty in Rad
85- 90 F6.1 pc Dist [64.1/1405.4] Distance
92- 95 F4.1 pc e_Dist [0.3/82.3] Lower limit uncertainty in Dist
97-101 F5.1 pc E_Dist [0.3/102] Upper limit uncertainty in Dist
103-107 F5.2 km/s vsini [1.8/12.9]? Rotational velocity
109-112 F4.2 km/s e_vsini [0.12/0.6]? Lower limit uncertainty in vsini
(1)
114-117 F4.2 km/s E_vsini [0.12/0.6]? Upper limit uncertainty in vsini
(1)
119-141 A23 --- Ref Source of the spectroscopic parameters used
as priors in our analysis (see Section 4.4)
143-161 A19 --- Bibcode Bibcode of the reference
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Note (1): The vsini uncertainties are internal to the Kea pipeline and do not
account for other types of line broadening; thus they are likely to be
underestimated.
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Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- EPIC EPIC identifier (EPIC NNNNNNNNN)
11- 14 F4.1 mag Kpmag [9.2/15.6] Kepler magnitude
16- 21 F6.3 d Porb [0.369/37.209] Orbital period
23- 29 F7.2 d T0 [2749.6/2776.76] Mid-transit time (BKJD)
31- 34 F4.1 h T14 [0.8/12.4] Duration of transit (1st to 4th
contact)
36- 42 F7.5 --- Depth [0.0001/0.05928] Transit depth
44- 47 F4.1 --- SDE [6.6/16.3] Signal detection efficiency
49- 52 F4.1 d Prot [7.2/39]? Rotational period
54- 57 F4.1 d e_Prot [1.1/11]? Lower limit uncertainty in Prot
59- 62 F4.1 d E_Prot [1.1/11]? Upper limit uncertainty in Prot
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- EPIC EPIC number (EPIC NNNNNNNNN.NN)
14- 19 F6.3 mag Kpmag [9.234/11.998] Kepler magnitude
21- 23 F3.1 m/s Kpred [1.2/5.7] Predicted Doppler semi-amplitude
25- 27 F3.1 m/s e_Kpred [0.4/2.2] Lower limit uncertainty in Kpred
29- 31 F3.1 m/s E_Kpred [0.5/2.3] Upper limit uncertainty in Kpred
33- 36 F4.2 Rgeo Rp [1.14/4.34] Planet radius
38- 44 F7.4 d Porb [0.3693/26.8199] Orbital period
46- 49 F4.1 d Prot [9.4/22]? Rotational period
51- 53 F3.1 d e_Prot [1.3/2.7]? Lower limit uncertainty in Prot
55- 57 F3.1 d E_Prot [1.3/6]? Upper limit uncertainty in Prot
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- EPIC EPIC number (EPIC NNNNNNNNN.NN)
14- 24 A11 --- Name Planet name
26- 33 F8.5 d Porb [0.36931/37.20364] Orbital period
35- 41 F7.5 d e_Porb [1e-05/0.03161] Lower limit uncertainty in Porb
43- 49 F7.5 d E_Porb [1e-05/0.0266] Upper limit uncertainty in Porb
51- 59 F9.4 d T0 [2749.59/2776.7633] Mid-transit time (BKJD)
61- 66 F6.4 d e_T0 [0.0002/0.0467] Lower limit uncertainty in T0
68- 73 F6.4 d E_T0 [0.0002/0.055] Upper limit uncertainty in T0
75- 78 F4.1 --- a1/R* [2.6/65.6] Scaled orbital distance
80- 83 F4.1 --- e_a1/R* [0.3/17.2] Lower limit uncertainty in a1/R*
85- 88 F4.1 --- E_a1/R* [0.1/11.6] Upper limit uncertainty in a1/R*
90- 93 F4.2 --- b [0.12/0.76] Impact parameter (b=acosi/R*)
95- 98 F4.2 --- e_b [0.01/0.34] Lower limit uncertainty in b
100-103 F4.2 --- E_b [0.01/0.36] Upper limit uncertainty in b
105-110 F6.4 --- Rp/R* [0.0083/0.1892] Planet-to-star radius ratio
112-117 F6.4 --- e_Rp/R* [0.0004/0.0062] Lower limit uncertainty in Rp/R*
119-124 F6.4 --- E_Rp/R* [0.0006/0.0057] Upper limit uncertainty in Rp/R*
126-131 F6.4 AU a2 [0.0095/0.2095] Scaled orbital distance
133-139 F7.5 AU e_a2 [4e-05/0.0047] Lower limit uncertainty in a2
141-147 F7.5 AU E_a2 [5e-05/0.0045] Upper limit uncertainty in a2
150-154 F5.2 Rgeo Rp [0.83/26.44] Planet radius
156-159 F4.2 Rgeo e_Rp [0.03/1.53] Lower limit uncertainty in Rp
161-164 F4.2 Rgeo E_Rp [0.06/1.55] Upper limit uncertainty in Rp
166-169 I4 K Teq [337/2336] Planet equilibrium temperature
171-173 I3 K e_Teq [3/106] Lower limit uncertainty in Teq
175-177 I3 K E_Teq [3/109] Upper limit uncertainty in Teq
179-183 F5.1 Mgeo Mp [0.7/184.3] Mass predicted (1)
185-188 F4.1 Mgeo e_Mp [0.4/79.4] Lower limit uncertainty in Mp
190-194 F5.1 Mgeo E_Mp [0.5/148.7] Upper limit uncertainty in Mp
196-199 F4.1 m/s Kpred [0.6/40.8] Predicted Doppler semi-amplitude
201-204 F4.1 m/s e_Kpred [0.4/17.6] Lower limit uncertainty in Kpred
206-209 F4.1 m/s E_Kpred [0.4/33] Upper limit uncertainty in Kpred
211 A1 --- l_rho* [<] Limit flag on rho*
212-216 F5.2 Sun rho* [0.05/10.8] Density of the host star
ρ*,LC
218-220 F3.1 Sun e_rho* [0/6.5]? Lower limit uncertainty in rho*
222-224 F3.1 Sun E_rho* [0/6.9]? Upper limit uncertainty in rho*
226-230 E5.1 --- FPP [1e-14/0.6] False Positive Probability
232-233 A2 --- Disp Disposition (2)
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Note (1): Using the mass-radius relation of Wolfgang et al. (2016, J/ApJ/825/19)
(see Section 6.4). We note that this mass-radius relation was calibrated with
sub-Neptunes similar in size to the vast majority of the planets in our
validated sample; the predictions may not be accurate for larger candidates,
but we report them here anyway for the sake of uniformity.
Note (2): The "Disposition" column indicates the final validation status of each
candidate:
VP = Validated planet;
PC = Planet candidate;
FP = False positive.
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Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- EPIC EPIC number (EPIC NNNNNNNNN.NN)
14- 19 E6.2 --- L-beb [0/0.0006] Likelihood that the signal is due to
a background eclipsing binary, at the measured
period
21- 26 E6.2 --- L-beb-Px2 [0/0.0014] Likelihood that the signal is due to
a background eclipsing binary, at twice the
measured period
28- 35 E8.2 --- L-eb [9.4e-114/0.0029] Likelihood that the signal is
due to an eclipsing binary, at the measured
period
37- 43 E7.2 --- L-eb-Px2 [1.4e-16/0.00039] Likelihood that the signal is
due to an eclipsing binary, at twice the
measured period
45- 52 E8.2 --- L-heb [7.7e-224/1.9e-05] Likelihood that the signal
is due to a hierarchical star system with an
eclipsing component, at the measured period
54- 61 E8.2 --- L-heb-Px2 [1.4e-102/1e-05] Likelihood that the signal
is due to a hierarchical star system with an
eclipsing component, at twice the measured
period
63- 68 E6.2 --- L-pl [0.00017/7.5] Likelihood that the signal is due
to a planet
70- 76 E7.2 --- FPP [9.5e-15/0.64] False Positive Probability
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Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- EPIC EPIC number (EPIC NNNNNNNNN.NN)
14- 17 F4.1 arcsec MaxRad [6.4/32.6] Maximum radius (the angular size of
the photometric aperture)
19- 22 E4.1 --- Thresh [1e-05/0.003] Secondary eclipse threshold (the
maximum secondary eclipse depth allowed by the
light curve)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- EPIC EPIC identifier (EPIC NNNNNNNNN)
11- 13 I3 nm Wave [562/832] Center wavelength of filter used
15- 16 I2 nm Width [40/44] Width of filter used
18- 28 A11 "date" Date Observation date
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Byte-by-byte Description of file: table11.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- EPIC EPIC number (EPIC NNNNNNNNN.NN)
14- 17 F4.2 --- g [0.26/2.12] Planet surface gravity, expressed in
units of Earth surface gravity (g⊕)
19- 22 I4 km H [96/1918] Atmospheric scale height
24- 27 I4 ppm deltaTS [26/2885] Expected amplitude of atmospheric
spectral features δTS
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Byte-by-byte Description of file: table12.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- EPIC EPIC number (EPIC NNNNNNNNN.NN)
14- 22 F9.6 d Porb [0.369293/37.2894] Orbital period
24- 31 F8.6 d e_Porb [7e-06/0.032089] Lower limit uncertainty in Porb
33- 40 F8.6 d E_Porb [7e-06/0.035237] Upper limit uncertainty in Porb
42- 44 F3.1 --- DeltaP [0/5.9] Difference in Porb, ΔP (in
σ units)
46- 51 F6.4 --- Rp/R* [0.0076/0.1879] Planet-to-star radius ratio
53- 58 F6.4 --- e_Rp/R* [0.0004/0.0119] Lower limit uncertainty in Rp/R*
60- 65 F6.4 --- E_Rp/R* [0.0004/0.0194] Upper limit uncertainty in Rp/R*
67- 69 F3.1 --- DeltaRp [0/5.3] Difference in Rp/R*, ΔRp (in
σ units)
71- 74 F4.2 --- b [0.21/0.9] Impact parameter (b=acosi/R*)
76- 79 F4.2 --- e_b [0.02/0.37] Lower limit uncertainty in b
81- 84 F4.2 --- E_b [0.02/0.39] Upper limit uncertainty in b
86- 88 F3.1 --- Deltab [0/1.2] Difference in b, Δb (in σ
units)
90- 93 F4.1 --- a/R* [2.9/68.6] Scaled orbital distance
95- 98 F4.1 --- e_a/R* [0.4/26.9] Lower limit uncertainty in a/R*
100-103 F4.1 --- E_a/R* [0.2/48.6] Upper limit uncertainty in a/R*
105-107 F3.1 --- Deltaa [0/1.4] Difference in a/R*, Δa (in σ
units)
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 08-Feb-2019