J/AJ/144/42 Infrared photometry of 90 KOIs (Adams+, 2012)
Adaptive optics images of Kepler Objects of Interest.
Adams E.R., Ciardi D.R., Dupree A.K., Gautier T.N., Kulesa C.,
McCarthy D.
<Astron. J., 144, 42 (2012)>
=2012AJ....144...42A 2012AJ....144...42A
ADC_Keywords: Stars, double and multiple ; Planets ; Photometry, infrared
Keywords: binaries: general - instrumentation: adaptive optics -
planets and satellites: detection
Abstract:
All transiting planets are at risk of contamination by blends with
nearby, unresolved stars. Blends dilute the transit signal, causing
the planet to appear smaller than it really is, or produce a
false-positive detection when the target star is blended with
eclipsing binary stars. This paper reports on high spatial-resolution
adaptive optics images of 90 Kepler planetary candidates. Companion
stars are detected as close as 0.1" from the target star. Images were
taken in the near-infrared (J and Ks bands) with ARIES on the MMT
and PHARO on the Palomar Hale 200inch telescope. Most objects (60%)
have at least one star within 6" separation and a magnitude difference
of 9. Eighteen objects (20%) have at least one companion within 2" of
the target star; six companions (7%) are closer than 0.5". Most of
these companions were previously unknown, and the associated planetary
candidates should receive additional scrutiny. Limits are placed on
the presence of additional companions for every system observed, which
can be used to validate planets statistically using the BLENDER
method. Validation is particularly critical for low-mass, potentially
Earth-like worlds, which are not detectable with current-generation
radial velocity techniques. High-resolution images are thus a crucial
component of any transit follow-up program.
Description:
Observations (in the J and Ks bands) with the Arizona Infrared
Imager and Echelle Spectrograph (ARIES) on the 6.5m MMT telescope were
taken on four nights between 2009 November and 2010 September (2009
Nov 11, 2010 May 2, 2010 May 3, 2010 Sep 24 and 2010 Sep 26).
Near-infrared adaptive optics imaging was obtained on the nights of
2009 September 7-10 and 2010 July 1-3 UT with the Palomar Hale 200inch
telescope and the PHARO near-infrared camera behind the Palomar
adaptive optics system. The KOIs observed in 2009 were imaged only in
the J filter while the KOIs observed in 2010 were imaged in the in
both the J and Ks filters.
All observations in the this paper are relative photometry.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 48 316 Limits on nearby stars for all KOIs
table4.dat 87 98 Stars within 6" of Kepler planetary candidates
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)
J/ApJ/736/19 : Kepler planetary candidates. II. (Borucki+, 2011)
J/AJ/142/19 : Speckle observations of KOI (Howell+, 2011)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- --- [K]
2- 6 I5 --- KOI [5/975] Kepler Object of Interest identifier
8- 12 A5 --- Inst Ground-based instrument used (ARIES or PHARO)
14- 16 A3 --- Filt Filter used (J, Ks or Kep)
18- 21 F4.2 arcsec FWHM ? Full-width half-maximum of stellar PSF
23- 25 F3.1 mag Dm0.1 ? Limiting differential magnitude at 0.1" (1)
27- 29 F3.1 mag Dm0.2 ? Limiting differential magnitude at 0.2" (1)
31- 33 F3.1 mag Dm0.5 ? Limiting differential magnitude at 0.5" (1)
35- 38 F4.1 mag Dm1 ? Limiting differential magnitude at 1" (1)
40- 43 F4.1 mag Dm2 Limiting differential magnitude at 2" (1)
45- 48 F4.1 mag Dm4 Limiting differential magnitude at 4" (1)
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Note (1): A series of concentric annuli are drawn around the star, and the
standard deviation of the background counts is calculated for each
annulus. A star is considered detectable if its peak signal is more
than five times the standard deviation above the background level.
The magnitude of this star is reported as the detection limit at the
distance of the center of the annulus.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1 A1 --- --- [K]
2- 6 I5 --- KOI [5/975] Kepler Object of Interest identifier
8- 15 I8 --- KIC ? Kepler Input Catalog identifier (Cat. V/133)
17- 22 F6.3 mag Kp0 [8.2/14.8]? Estimated magnitude of the
target star in Kepler band (Cat. V/133)
24- 29 F6.3 mag Jmag [7.229/12.71]? Magnitude of the target star
in 2MASS J band (from Cat. V/133)
31- 36 F6.3 mag Kmag [6.945/12.336]? Magnitude of the target
star in 2MASS Ks band (from Cat. V/133)
38 A1 --- Inst [AP] Ground-based instrument used:
A=ARIES or P=PHARO
40 I1 --- Star [1/5] Companion star identifier (1)
42- 45 F4.2 arcsec r(J) ? Distance of the companion star from the
target star (in the J band)
47 A1 --- f_r(J) [fg] unreliable r(J) (2)
49- 53 F5.1 deg PA(J) ? Position angle of the companion star
(in the J band) (3)
55- 59 F5.2 mag DJ ? Observed delta relative J magnitude
(error is about 0.01 mag)
61 A1 --- f_DJ [g] unreliable DJ (2)
63- 66 F4.2 arcsec r(Ks) ? Distance of the companion star from the
target star (in the Ks band)
68 A1 --- f_r(Ks) [g] unreliable r(Ks) (2)
70- 74 F5.1 deg PA(Ks) ? Position angle of the companion star
(in the Ks band) (3)
76- 80 F5.2 mag DKs ? Observed delta relative Ks magnitude
(error is about 0.01 mag)
82 A1 --- f_DKs [g] unreliable DKs (2)
84- 87 F4.1 mag Kpmag [10/24]? Estimated magnitude of the companion
star in Kepler's broad optical band (4)
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Note (1): Each unique companion star detected is numbered. The same number is
used for both ARIES and PHARO observations of the same star.
Note (2): Flag as follows:
f = Due to the large, smeared PSF, the parameters for K00013 in ARIES-J
are not considered reliable.
g = Companion distance was near or below the FWHM, so magnitudes were
estimated using PSF fitting.
Note (3): Angle from north. Note that the ARIES angles were determined from
the northeast directions of the dither pattern, which sometimes had
random jitter, and may differ from the true angle by a few degrees.
Note (4): Estimated for a dwarf companion using Equation (3) if both J and
Ks are available, and otherwise from Equations (1) or (2).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 02-Oct-2013