J/A+A/576/A88 Radial velocities of 8 KOI eclipsing binaries (Lillo-Box+, 2015)
Eclipsing binaries and fast rotators in the Kepler sample.
Characterization via radial velocity analysis from Calar Alto.
Lillo-Box J., Barrado D., Mancini L., Henning T., Figueira P., Ciceri S.,
Santos N.
<Astron. Astrophys., 576, A88-88 (2015)>
=2015A&A...576A..88L 2015A&A...576A..88L
ADC_Keywords: Binaries, eclipsing - Radial velocities
Keywords: techniques: radial velocities - planets and satellites: general -
binaries: eclipsing - binaries: close
Abstract:
The Kepler mission has searched for planetary transits in more than
two hundred thousand stars by obtaining very accurate photometric data
over a long period of time. Among the thousands of detected
candidates, the planetary nature of around 15% has been established or
validated by different techniques. But additional data are needed to
characterize the rest of the candidates and reject other possible
configurations. We started a follow-up program to validate, confirm,
and characterize some of the planet candidates. In this paper we
present the radial velocity analysis of those that present large
variations, which are compatible with being eclipsing binaries. We
also study those showing high rotational velocities, which prevents us
from reaching the necessary precision to detect planetary-like
objects. We present new radial velocity results for 13 Kepler objects
of interest (KOIs) obtained with the CAFE spectrograph at the Calar
Alto Observatory and analyze their high-spatial resolution (lucky)
images obtained with AstraLux and the Kepler light curves of some
interesting cases. We have found five spectroscopic and eclipsing
binaries (group A). Among them, the case of KOI-3853 is of particular
interest. This system is a new example of the so-called heartbeat
stars, showing dynamic tidal distortions in the Kepler light curve. We
have also detected duration and depth variations of the eclipse. We
suggest possible scenarios to explain such an effect, including the
presence of a third substellar body possibly detected in our radial
velocity analysis. We also provide upper mass limits to the transiting
companions of six other KOIs with high rotational velocities
(group B). This property prevents the radial velocity method from
achieving the necessary precision to detect planetary-like masses.
Finally, we analyze the large radial velocity variations of two other
KOIs, which are incompatible with the presence of planetary-mass
objects (group C). These objects are likely to be stellar binaries.
However, a longer timespan is needed to complete their
characterization.
Description:
We have obtained multi-epoch RV data for the 13 KOIs.
We used the CAFE instrument mounted on the 2.2m telescope at Calar
Alto Observatory (Almeria Spain) to obtain high-resolution spectra
(R=59000-67000) in the optical range (4000-9000Å).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 98 13 *Kepler Objects of Interest analyzed in this work
tablea.dat 49 403 Measured radial velocities (tables A1-A13)
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Note on table2.dat: Observational data obtained with CAFE at Calar Alto
Observatory.
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/ApJ/736/19 : Kepler planetary candidates. II. (Borucki+, 2011)
J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)
J/ApJS/211/2 : Q1-16 Kepler targets revised stellar properties (Huber+, 2014)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- Group [ABC] Group (1)
3- 9 F7.2 --- KOI KOI designation
11- 14 F4.1 --- kepmag Kepler magnitude
16- 17 I2 h RAh Simbad right ascension (J2000)
19- 20 I2 min RAm Simbad right ascension (J2000)
22- 26 F5.2 s RAs Simbad right ascension (J2000)
28 A1 --- DE- Simbad declination sign (J2000)
29- 30 I2 deg DEd Simbad declination (J2000)
32- 33 I2 arcmin DEm Simbad declination (J2000)
35- 39 F5.2 arcsec DEs Simbad declination (J2000)
40 A1 --- Note [*] Position corrected at CDS (2)
41- 52 F12.7 d Per [1.5/1065] Transit period (3)
54- 62 F9.7 d e_Per rms uncertainty on Period
64 A1 --- n_Per [d] Period is halved (4)
66- 69 F4.2 Msun M* [0.8/2.6] Stellar masses are obtained from
Huber et al. 2014 (J/ApJS/211/2)
71- 74 F4.2 Msun e_M* [0.07/0.53] rms uncertainty on M*
76- 81 F6.4 Rsun Rtr Radius of the transiting companions (5)
83- 88 F6.4 Rsun e_Rtr ? rms uncertainty on Rtr
89 A1 --- n_Rtr [ab] Origin of Rtr (6)
91- 92 I2 -- Nsp [10/52] Number of spectra
94- 98 F5.1 d Tspan [17/722] Time span
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Note (1): Groups as follows:
A = Eclipsing binaries
B = Fast rotators
C = Unsolved cases
Note (2): In original table2, the positions of KOI-3853.01, KOI-3728.01 and
KOI-3890.01 were inverted, corrected by CDS in this table version.
Note (3): Transit periods are obtained from Borucki et al.
(2011ApJ...736...19B 2011ApJ...736...19B, Cat. J/ApJ/736/19) and Batalha et al.
(2013ApJS..204...24B 2013ApJS..204...24B, Cat. J/ApJS/204/24).
Note (4): In Sect. Sect. 4, we have demonstrated that the actual period of
this system is twice this value, i.e., 3.1409940±.0000008 days.
Note (5): Radius of the transiting compnions according to Batalha et al.
(2013ApJS..204...24B 2013ApJS..204...24B, Cat. J/ApJS/204/24).
Note (6): Notes as follows:
a = This radius was obtained from our own transit fitting (see Sect. 4)
b = In this case, the radius of the companion was obtained from Diaz et al.
(2014A&A...572A.109D 2014A&A...572A.109D)
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Byte-by-byte Description of file: tablea.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [KOI-]
5- 8 I04 --- KOI KOI star number (without decimal)
11- 20 F10.6 d JD Julian date (JD-2456000)
22- 25 F4.1 --- S/N Average signal-to-noise ratio (1)
27- 34 F8.3 km/s RV Radial velocity
36- 41 F6.3 km/s E_RV Error on RV (upper value)
44- 49 F6.3 km/s e_RV Error on RV (lower value)
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Note (1): calculated as the median signal over the measured scatter of a
continuum region close to 5500Å.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 01-Jun-2015