J/ApJ/787/47 106 Kepler ultra-short-period planets (Sanchis-Ojeda+, 2014)
A study of the shortest-period planets found with Kepler.
Sanchis-Ojeda R., Rappaport S., Winn J.N., Kotson M.C., Levine A.,
El Mellah I.
<Astrophys. J., 787, 47 (2014)>
=2014ApJ...787...47S 2014ApJ...787...47S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Planets ; Effective temperatures ;
Stars, diameters
Keywords: planetary systems - planets and satellites: atmospheres -
planets and satellites: detection
Abstract:
We present the results of a survey aimed at discovering and studying
transiting planets with orbital periods shorter than one day
(ultra-short-period, or USP, planets), using data from the Kepler
spacecraft. We computed Fourier transforms of the photometric time
series for all 200000 target stars, and detected transit signals
based on the presence of regularly spaced sharp peaks in the Fourier
spectrum. We present a list of 106 USP candidates, of which 18 have
not previously been described in the literature. This list of
candidates increases the number of planet candidates with orbital
periods shorter than about six hours from two to seven. In addition,
among the objects we studied, there are 26 USP candidates that had
been previously reported in the literature which do not pass our
various tests. All 106 of our candidates have passed several standard
tests to rule out false positives due to eclipsing stellar systems. A
low false positive rate is also implied by the relatively high
fraction of candidates for which more than one transiting planet
signal was detected. By assuming these multi-transit candidates
represent coplanar multi-planet systems, we are able to infer that the
USP planets are typically accompanied by other planets with periods in
the range 1-50 days, in contrast with hot Jupiters which very rarely
have companions in that same period range. Another clear pattern is
that almost all USP planets are smaller than 2 R{earth}, possibly
because gas giants in very tight orbits would lose their atmospheres
by photoevaporation when subject to extremely strong stellar
irradiation. Based on our survey statistics, USP planets exist around
approximately (0.51±0.07)% of G-dwarf stars, and (0.83±0.18)% of
K-dwarf stars.
Description:
To carry out an independent search for the shortest-period planets, we
used the Kepler long-cadence time-series photometric data (30 minute
samples) obtained between quarters 0 and 16. A list was prepared of
all ∼200000 target stars for which photometry is available for at
least one quarter, and the version 5.0 FITS files, which were
available for all quarters, were downloaded from the STScI MAST Web
site. For estimates of basic stellar properties including not only
radii, but also masses and effective temperatures, we relied on the
catalog of Huber et al. (2014, J/ApJS/211/2). This catalog is based on
a compilation of photospheric properties derived from many different
sources. Although it is not a homogeneous catalog, it likely provides
the most accurate stellar parameters that are currently available.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 148 106 Characteristics of the 106 USP Planet Candidates
Discovered in the Kepler Data
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/A+A/555/A58 : New Kepler planetary candidates (Ofir+, 2013)
J/MNRAS/429/2001 : New transiting planet candidates from Kepler (Huang+, 2013)
J/ApJS/211/2 : Revised stellar properties of Q1-16 Kepler targets
(Huber+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Group [ABC] Planet candidate group (1)
3- 10 A8 --- KIC KIC number (KIC NNNNNNNN in Simbad)
12- 18 F7.2 --- KOI KOI number (KOI -NNNN.NN in Simbad) (2)
20- 23 F4.1 mag Kpmag Kepler magnitude
25- 28 I4 K Teff Effective temperature
30- 32 I3 K E_Teff Upper limit uncertainty in Teff
34- 36 I3 K e_Teff Lower limit uncertainty in Teff
38- 41 F4.2 [cm/s2] logg Surface gravity
43- 46 F4.2 [cm/s2] E_logg Upper limit uncertainty in logg
48- 51 F4.2 [cm/s2] e_logg Lower limit uncertainty in logg
53- 56 F4.2 Rsun R* Stellar radius
58- 61 F4.2 Rsun E_R* Upper limit uncertainty in R*
63- 66 F4.2 Rsun e_R* Lower limit uncertainty in R*
68- 77 F10.8 d Porb Orbital period
79- 89 F11.6 d t0 The midtransit time (BJD-2454900)
91- 94 I4 ppm Depth Transit depth
96- 97 I2 ppm E_Depth Upper limit uncertainty in Depth
99-100 I2 ppm e_Depth Lower limit uncertainty in Depth
102-106 F5.3 h Dur Transit duration
108-112 F5.3 h E_Dur Upper limit uncertainty in Dur
114-118 F5.3 h e_Dur Lower limit uncertainty in Dur
120-123 F4.2 --- a/R* The inverse transit probability
125-128 F4.2 --- E_a/R* Upper limit uncertainty in a/R*
130-133 F4.2 --- e_a/R* Lower limit uncertainty in a/R*
135-138 F4.2 Rgeo Rp Planet radius
140-143 F4.2 Rgeo E_Rp Upper limit uncertainty in Rp
145-148 F4.2 Rgeo e_Rp Lower limit uncertainty in Rp
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Note (1): Group as follows:
A = New planet candidates. These objects either emerged from our search for
the first time, or appear on the KOI list as false positives but that we
consider to be viable candidates;
B = The 69 KOIs that passed our false positive tests (Akeson et al.
2013PASP..125..989A 2013PASP..125..989A);
C = 19 other candidates that were discovered by other authors
(Ofir & Dreizler 2013, J/A+A/555/A58; Huang et al. 2013,
J/MNRAS/429/2001; Jackson et al. 2013ApJ...779..165J 2013ApJ...779..165J).
Note (2): Planets discovered transiting stars with other KOI planets with no
KOI number assigned are labeled with the KOI of the star followed by
a dot and two zeros.
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History:
From electronic version of the journal
(End) Prepared by Tiphaine Pouvreau [CDS] 23-Jun-2017