J/AJ/161/21 383 KOIs interferometry with WIYN (Colton+, 2021)
Identifying bound stellar companions to Kepler exoplanet host stars using
Speckle imaging.
Colton N.M., Horch E.P., Everett M.E., Howell S.B., Davidson J.W.,
Baptista B.J., Casetti-Dinescu D.I.
<Astron. J., 161, 21 (2021)>
=2021AJ....161...21C 2021AJ....161...21C
ADC_Keywords: Stars, double and multiple; Optical; Positional data;
Proper motions; Parallaxes, trigonometric
Keywords: Visual binary stars ; Interferometric binary stars ;
Planet hosting stars ; Speckle interferometry ; Astrometry
Abstract:
The Kepler mission and subsequent ground-based follow-up observations
have revealed a number of exoplanet host stars with nearby stellar
companions. This study presents speckle observations of 57 Kepler
objects of interest (KOIs) that are also double stars, each observed
over a 3-8yr period, which has allowed us to track their relative
motions with high precision. Measuring the position angle and
separation of the companion with respect to the primary can help
determine if the pair exhibits common proper motion, indicating it is
likely to be a bound binary system. We report on the motions of 34
KOIs that have close stellar companions, three of which are triple
stars, for a total of 37 companions studied. Eighteen of the 34
systems are confirmed exoplanet hosts, including one triple star,
while four other systems have been subsequently judged to be false
positives and twelve are yet to be confirmed as planet hosts. We find
that 21 are most likely to be common proper motion pairs, 4 are
line-of-sight companions, and 12 are of an uncertain disposition at
present. The fraction of the confirmed exoplanet host systems that are
common proper motion pairs is approximately 86% in this sample. In
this subsample, the planets are exclusively found with periods of less
than 110 days, so that in all cases the stellar companion is found at
a much larger separation from the planet host star than the planet
itself. A preliminary period-radius relation for the confirmed planets
in our sample suggests no obvious differences at this stage with the
full sample of known exoplanets.
Description:
Two different speckle instruments were used for work on this project.
The majority of the observations were taken with the Differential
Speckle Survey Instrument (DSSI), which was completed in 2008 at
Southern Connecticut State University and subsequently became a
visitor instrument at the University of Wisconsin-Madison, Indiana
University, and Yale University (WIYN) Telescope.
In 2016, a successor instrument to DSSI, the NN-EXPLORE Exoplanet
Stellar Speckle Imager (NESSI), was completed and began operations at
WIYN. In the 2016B and 2017A observing semesters, NESSI was used to
obtain further observations of KOIs known to have close stellar
companions.
The DSSI filters had center wavelengths of 692 and 880nm, with an FWHM
of 40 and 50nm respectively; for NESSI observations, the filters were
centered at 562 and 832nm, with FWHM transmission of 44 and 40nm,
respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 383 KOI double star Speckle measures
table2.dat 98 37 Proper motions for KOIs observed in at least 3 epochs
table3.dat 86 37 Final properties of 37 KOI double Star components
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See also:
B/simbad : Simbad objects catalogue (M.Wenger 2000)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2020)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/PASP/110/863 : A Stellar Spectral Flux Library: 1150 - 25000 A (Pickles 1998)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/AJ/141/45 : Speckle observations of HIP stars (Horch+, 2011)
J/AJ/142/19 : Speckle observations of KOI (Howell+, 2011)
J/AJ/150/151 : DSSI obs. of binaries. VI. Measures in 2014 (Horch+, 2015)
J/ApJ/813/130 : Kepler multiple transiting planet systems (Wang+, 2015)
J/ApJ/813/130 : Kepler multiple transiting planet systems (Wang+, 2015)
J/AJ/152/8 : Impact stellar multiplicity planetary systems I (Kraus+, 2016)
J/AJ/153/25 : Near-infrared observations of 84 KOI systems (Atkinson+, 2017)
J/AJ/154/109 : California-Kepler Survey. III. Planet radii (Fulton+, 2017)
J/AJ/153/71 : Kepler follow-up observation program I. Imaging (Furlan+,2017)
J/AJ/153/117 : KOIs companions from high-resolution imaging (Hirsch+, 2017)
J/AJ/153/212 : Observations of binary stars at WIYN telescope (Horch+, 2017)
J/AJ/155/136 : Planets orbiting bright stars K2 campaigns 0-10 (Mayo+, 2018)
J/AJ/156/83 : Effect of stellar companions planetary systems (Ziegler+,2018)
J/AJ/158/113 : Kepler-13AB aperture photometry (Howell+, 2019)
J/A+A/623/A117 : Galactic Cepheids & RR Lyrae multiplicity. II (Kervella+,2019)
J/AJ/159/19 : SOAR TESS survey. I. (Ziegler+, 2020)
http://exofop.ipac.caltech.edu/ : Kepler Follow-up Observing Program
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- KOI Kepler Object of Interest number
6- 7 A2 --- Comp Component identifier, if the system is triple
9- 19 A11 --- Kepler Kepler exoplanet system number
21- 30 A10 --- WDS Washington Double Star number, based on J2000
position, HHMMm+DDMM
32- 38 F7.4 yr Date [10.4/17.4] Besselian date of the observation,
offset 2000+
40- 44 F5.1 deg PA [21.2/355] Position angle of the secondary star
relative to the primary (1)
46- 51 F6.4 arcsec Sep [0.06/2] Separation of the two stars
53- 53 A1 --- l_dmag limit flag on dmag
55- 58 F4.2 mag dmag [0/6.09] Magnitude difference
60- 62 I3 nm lambda [562/880] Center wavelength of the filter used
64- 65 I2 nm FWMH [40/50] Full width at half maximum of the filter
transmission
67- 72 A6 --- Notes Telescope, Instrument, and Notes (2)
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Note (1): North through East defining the positive sense of PA
Note (2): Notes as follows :
GD = Gemini-North Telescope, DSSI;
LD = Lowell Discovery Telescope, DSSI;
WD = WIYN Telescope, DSSI;
WN = WIYN Telescope, NESSI;
a = The magnitude difference appears here as an upper limit due to the
speckle decorrelation effect discussed in the text;
b = The position angle has been changed by 180 degrees to be consistent with
other measures in the table or earlier measures in the literature.
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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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1- 4 I4 --- KOI Kepler Object of Interest number
5- 6 A2 ---- Comp Component identifier, if the system is triple
9- 12 I4 --- Kepler ? Kepler number, if a confirmed exoplanet host
(1)
14- 15 A2 --- f_Kepler Disposition if unconfirmed (1)
17- 23 F7.3 mas/yr DpmRA [-19.7/4.16] Speckle relative proper motion in
right ascension
25- 29 F5.3 mas/yr e_DpmRA [0.11/8.7] Uncertainty in the speckle relative
proper motion in right ascension
31- 37 F7.3 mas/yr DpmDE [-43/7.02] Speckle relative proper motion in
declination
39- 43 F5.3 mas/yr e_DpmDE [0.16/5.7] Uncertainty in the speckle relative
proper motion in declination
45- 52 F8.3 mas/yr pmRA [-145/27] System proper motion in right
ascension
54- 58 F5.3 mas/yr e_pmRA [0.03/8] Uncertainty in the system proper
motion in right ascension
60- 67 F8.3 mas/yr pmDE [-401/35.7] System proper motion in declination
69- 73 F5.3 mas/yr e_pmDE [0.04/8] Uncertainty in the system proper
motion in declination
75- 79 F5.3 mas plx [0.56/8.73]? Parallax
81- 85 F5.3 mas e_plx [0.02/1.16]? Uncertainty in the parallax
87- 98 A12 --- Ref Source for system proper motion and parallax (2)
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Note (1): If no Kepler number exists, the disposition as either a planetary
candidate (PC) or false positive (FP) is given, based on information
available on the Kepler Community Follow-up Observing Program (CFOP)
website, https://exofop.ipac.caltech.edu/cfop.php.
Note (2): Sources as follows:
CFOP = Kepler Community Follow-up Observing Program website,
DR2 = Gaia Collaboration (I/345), in this case it is the source of both
parallax and the proper motion;
Tycho-2 = Hog+, 2000, I/259);
UCAC4 = Zacharias+, 2013AJ....145...44Z 2013AJ....145...44Z
c = The pair is resolved in Gaia DR2, so the values given in this line
are for the primary star.
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- KOI Kepler Object of Interest number
5- 6 A2 --- Comp Component identifier, if the star is triple
8- 11 I4 --- Kepler ? Kepler number (1)
13- 14 A2 --- f_Kepler Disposition if unconfirmed (1)
16- 16 I1 --- Np [1/4]? Number of planets
18- 23 F6.1 pc Dist [114/1946]? Distance to the system
25- 30 F6.1 pc E_Dist [0.4/2181]? Error bar in the distance measure in
the positive direction
32- 36 F5.1 pc e_Dist [0.4/946]? Error bar in the distance measure in
the negative direction
38- 41 F4.2 Msun M1 [0.24/2] Estimated Mass of the Primary Star (2)
43- 46 F4.2 Msun M2 [0.22/1.48] Estimated Mass of the Secondary Star
(2)
48- 48 A1 --- f_M2 X=not a CPM pair (3)
50- 55 F6.4 --- R1 [0.008/1.95] The ratio R1 for the system
57- 62 F6.4 --- e_R1 [0.004/1.02]The uncertainty in R1
64- 69 F6.2 --- R2 [0.3/309]? The ratio R2 for the system
71- 76 F6.2 --- e_R2 [0.08/184]? The uncertainty in R2
78- 86 A9 --- Notes The final determination of motion of the system
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Note (1):If no Kepler number is given, the disposition as either a planetary
candidate (PC) or false positive (FP) is given, based on information
available on the Kepler CFOP website,
https://exofop.ipac.caltech.edu/cfop.php.
Note (2): The uncertainty in all values in this column is assumed to be 0.1
solar masses.
Note (3): Calculated under the assumption that the companion is bound. If the
system is not judged to be a CPM pair then f_M2 is equal to 'X'.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 26-Feb-2021