Padova University
Padova University
Astronomy Department
Physics & Astronomy Dep.
Asiago Observatory
Padova Observatory
Padova Observatory

Exoplanets & Stellar Populations Group

vicolo Osservatorio 3, 35122 Padova - Italy tel. +39.049.827.8211     fax. +39.049.827.8212

A PSF-based approach to Kepler/K2

Libralato et al. (2016) MNRAS, 456, 1137

Kepler and K2 data analysis reported in the literature is mostly based on aperture photometry. Because of Kepler's large, undersampled pixels and the presence of nearby sources, aperture photometry is not always the ideal way to obtain high-precision photometry and, because of this, the data set has not been fully exploited so far.
We present a new method (Libralato et al., 2016 MNRAS, 456, 1137) that builds on our experience with undersampled HST images. The method involves a point-spread function (PSF) neighbour subtraction and was specifically developed to exploit the huge potential offered by the K2 "super-stamps" covering the core of dense star clusters, but our technique is perfectly suitable to also analyse sparse fields imaged in single, isolated stamps.
By using a high-angular-resolution catalogue and PSFs we are able to pinpoint each star in the adopted input catalogue into each Kepler/K2 exposure and to measure its flux after all detectable close-by neighbours are subtracted from the image. This PSF-based technique allows us to (i) increase the number of analysable objects in the field, (ii) estimate an unbiased flux for a given source, (iii) extract the light curve of a star in a crowded environment and (iv) improve the photometric precision reachable for faint stars.
We are currently working on different stellar clusters imaged during K2 Campaigns and Kepler main mission.

Related papers to Kepler/K2 data analysis: In the table below, together with all light curves (6-th column), we release other useful material such as input catalogs, variable and exoplanet-candidate catalogs, stacked images. All files can be found in each channel folder (7-th column).

Due to the large number of the files stored, we warn the Users that the redirect may take a few moments.
"Don't abandon all hope, ye who enter here!" (semicit.)

MissionCampaignCluster IDModuleChannelElectronic materialPapersReadme file
K20M 35 + NGC 21582481LCsAll filesPaper IReadme.txt
K25M 4414 (*)45LCsAll filesPaper IIReadme.txt
46LCsAll files
47LCsAll files
48LCsAll files
M 67613LCsAll filesPaper IIIReadme.txt
14LCsAll files

(*) Note that for M 44 the input and the variable/exoplanet catalogs in each Module-14 channel folder are the same. We copied them into each channel folder for sake of completeness.