J/PASP/124/1279 Q3 Kepler's combined photometry (Christiansen+, 2012)
The derivation, properties, and value of Kepler's combined differential
photometric precision.
Christiansen J.L., Jenkins J.M., Caldwell D.A., Burke C.J., Tenenbaum P.,
Seader S., Thompson S.E., Barclay T.S., Clarke B.D., Li J., Smith J.C.,
Stumpe M.C., Twicken J.D., Van Cleve J.
<Publ. Astron. Soc. Pac., 124, 1279-1287 (2012)>
=2012PASP..124.1279C 2012PASP..124.1279C
ADC_Keywords: Surveys ; Stars, double and multiple ; Planets
Keywords: extrasolar planets
Abstract:
The Kepler Mission is searching for Earth-size planets orbiting
solar-like stars by simultaneously observing >160000 stars to detect
sequences of transit events in the photometric light curves. The
Combined Differential Photometric Precision (CDPP) is the metric that
defines the ease with which these weak terrestrial transit signatures
can be detected. An understanding of CDPP is invaluable for evaluating
the completeness of the Kepler survey and inferring the underlying
planet population. This paper describes how the Kepler CDPP is
calculated, and introduces tables of rms CDPP on a per-target basis
for 3-, 6-, and 12-hr transit durations, which are now available for
all Kepler observations. Quarter 3 is the first typical set of
observations at the nominal length and completeness for a quarter,
from 2009 September 18 to 2009 December 16, and we examine the
properties of the rms CDPP distribution for this data set. Finally, we
describe how to employ CDPP to calculate target completeness, an
important use case.
Description:
For users interested in the ensemble noise statistics, for instance
those performing completeness calculations, tables of the rms CDPP
values for the planetary targets are being made available from the
MAST Kepler website (http://archive.stsci.edu/pub/kepler/catalogs/)
starting with all the publicly released data up to Quarter 10. In
Table 1 contains the table for Quarter 3, demonstrating the format and
content. For users working with individual targets, the 3-, 6-, and
12-hr rms CDPP values are stored in the headers of the individual
light curve FITS files, also available at the MAST website. As the
data are reprocessed with improved versions of the SOC pipeline, the
FITS files are replaced at MAST and will contain updated rms CDPP
values.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 140 167042 Q3 table of rms Combined Differential Photometric
Precision (CDPP)
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
http://archive.stsci.edu/kepler/ : Kepler archives Home Page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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2- 9 I8 --- KIC [757076/12984227] KIC number
12- 17 F6.3 mag Kpmag ?=0 Kepler magnitude
20- 21 I2 --- m [2/24] Module on which the target is located
in that quarter
24 I1 --- o [1/4] Output on which the target is located
in that quarter
27- 30 I4 --- i [14/1109] Column location of the KIC position
of the target
33- 36 I4 --- j [22/1042] Row location of the KIC position
of the target
39- 43 F5.3 --- Contam [0/1] Fraction of the flux in the target
aperture that is not from the target star
46- 50 I5 K Teff [0/19337] Effective temperature from KIC
53- 57 F5.3 [cm/s2] logg Gravity surface from KIC
59- 65 F7.3 Rsun R* Stellar radius from KIC
68- 72 F5.3 mag g-r SDSS g-r colour from KIC
75- 79 F5.3 mag J-K J-K colour from KIC
84- 85 I2 --- DRN [14] Data release number from the processing
with which the CDPP values were calculated
87- 96 F10.3 ct rms3 ?=0 rms combined differential photometric
precision over 3 hrs
98-107 F10.3 ct rms6 ?=0 rms combined differential photometric
precision over 6 hrs
109-118 F10.3 ct rms12 ?=0 rms combined differential photometric
precision over 12 hrs
121-140 A20 --- PID Program ID of the target
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History:
Copied at http://archive.stsci.edu/pub/kepler/catalogs/
(End) Patricia Vannier [CDS] 26-Mar-2013