J/AJ/156/22 Planetary candidates from K2 Campaign 16 (Yu+, 2018)
Planetary candidates from K2 Campaign 16.
Yu L., Crossfield I.J.M., Schlieder J.E., Kosiarek M.R., Feinstein A.D.,
Livingston J.H., Howard A.W., Benneke B., Petigura E.A., Bristow M.,
Christiansen J.L., Ciardi D.R., Crepp J.R., Dressing C.D., Fulton B.J.,
Gonzales E.J., Hardegree-Ullman K.K., Henning T., Isaacson H., Lepine S.,
Martinez A.O., Morales F.Y., Sinukoff E.
<Astron. J., 156, 22-22 (2018)>
=2018AJ....156...22Y 2018AJ....156...22Y (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets ; Stars, double and multiple ; Stars, diameters ;
Stars, masses ; Effective temperatures ; Photometry
Keywords: methods: data analysis - planets and satellites: detection -
techniques: photometric
Abstract:
Given that Campaign 16 of the K2 mission is one of just two K2 campaigns
observed so far in "forward-facing" mode, which enables immediate
follow-up observations from the ground, we present a catalog of interesting
targets identified through photometry alone. Our catalog includes 30
high-quality planet candidates (showing no signs of being non-planetary
in nature), 48 more ambiguous events that may be either planets or false
positives, 164 eclipsing binaries, and 231 other regularly periodic
variable sources. We have released light curves for all targets in C16
and have also released system parameters and transit vetting plots for all
interesting candidates identified in this paper. Of particular interest
is a candidate planet orbiting the bright F dwarf HD 73344 (V=6.9, K=5.6)
with an orbital period of 15 days. If confirmed, this object would
correspond to a 2.56±0.18 R⊕ planet and would likely be a
favorable target for radial velocity characterization. This paper is
intended as a rapid release of planet candidates, eclipsing binaries,
and other interesting periodic variables to maximize the scientific yield
of this campaign, and as a test run for the upcoming TESS mission, whose
frequent data releases call for similarly rapid candidate identification
and efficient follow up.
Description:
We provide a rapid, public release of light curves, planet candidates,
and other interesting periodic variables from K2's Campaign 16 (C16)
in this paper. During C16, K2 observed 20647 stars in a field centered
at RA=08:54:50, DE=+18:31:31, for a period of 80 days between 2017
December 07 and 2018 February 25. This is only the second campaign in
which the spacecraft was pointed along the forward-facing direction of
its velocity vector. Forward-facing observations enable simultaneous
observations from the ground and with K2, and they also allow the field
to be accessed from ground-based observatories as soon as compelling
targets can be identified. C16 also overlaps with C5 except for a
40-px-wide strip that is not on silicon in C16. We find that 6167 targets
observed in C16 were also observed in C5. Raw cadence pixel data for C16
became available on the Mikulski Archive for Space Telescopes (MAST) on
2018 February 28.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 265 30 High-quality candidate parameters
table2.dat 265 48 Plausible candidate parameters
table3.dat 157 170 Systems with secondary eclipses
table4.dat 157 231 Systems showing periodic variability
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See also:
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
J/ApJ/809/25 : Stellar and planet properties for K2 candidates
(Montet+, 2015)
J/A+A/594/A100 : K2 new planetary and EB candidates (Barros+, 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)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 12 F12.2 --- Name Candidate identifier (EPIC NNNNNNNNN.NN in
Simbad)
13 A1 --- n_Name [bc] Note on Name (1)
15- 20 F6.3 mag Kpmag [6.793/18.174] Kepler magnitude
22- 30 F9.6 d Per [0.53027/30.954222] Period
32- 41 F10.5 d T0 [3262.55671/3285.09327] Time of periastron
T0 (BJD-2454833)
43- 48 F6.4 d T14 [0.0311/0.3209] Duration of transit (1st to
4th contact) T14
50- 55 I6 ppm (Rp/R*)2 [149/696741] Square of the planet-to-star
radius ratio (Rp/R*)2
57- 62 F6.3 Rsun R* [0.189/10.091] Stellar radius
64- 68 F5.3 Rsun e_R* [0.003/0.531] Uncertainty in R* (2)
70- 74 F5.3 Msun M* [0.103/3.49] Stellar mass
76- 80 F5.3 Msun e_M* [0.004/0.558] Uncertainty in M* (2)
82- 86 I5 K Teff [2980/11500] Effective temperature
88- 91 I4 K e_Teff [10/1960] Uncertainty in Teff (2)
93- 97 F5.3 [cm/s2] logg [2.964/5.092] Surface gravity (in cgs units)
99-103 F5.3 [cm/s2] e_logg [0.009/0.581] Uncertainty in logg (2)
105-108 F4.1 Rgeo Rp [1.4/18.3]? Planet radius (only in Table 1)
110-113 I4 Earth Sinc [3/2815]? Incident irradiation (only in
Table 1)
115-117 A3 --- C5 [yes ] Target also observed in Campaign 5?
119-169 A51 --- Com Comment
171-210 A40 --- Bibcode Bibcode of the reference(s) in Com
212-265 A54 --- Ephem Ephemeris matching (only in Table 2)
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Note (1): Note as follows:
b = Parameters not in EPIC; classified using isochrones as described in
Section 1;
c = Possible multi, but the ephemeris of 251319382.01 matches that of another
Threshold-crossing Event (TCE) (see Table 2). We identified hints of a
third candidate in this system, with a period of ∼3.5 day and S/N∼7.
Note (2): Note that all uncertainties reported in this table are statistical
uncertainties only and do not account for systematic uncertainties in the
underlying stellar models.
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Byte-by-byte Description of file: table3.dat table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.2 --- Name Candidate identifier (EPIC NNNNNNNNN.NN in
Simbad)
14- 19 F6.3 mag Kpmag [7.605/20.14] Kepler magnitude
21- 29 F9.6 d Per [0.491506/26.286249] Period
31- 40 F10.5 d T0 [3262.46826/3277.84155]? Time of periastron T0
(BJD-2454833) (only in Table 3)
42- 47 F6.4 d T14 [0.0239/0.6392]? Duration of transit (1st to 4th
contact) T14 (only in Table 3)
49- 55 I7 ppm (Rp/R*)2 [228/1355446]? Square of the planet-to-star
radius ratio (Rp/R*)2 (only in Table 3)
57- 59 A3 --- C5 [yes ] Target also observed in Campaign 5?
61-102 A42 --- Com Comment
104-157 A54 --- Ephem Ephemeris matching
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 10-Jan-2019