English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Observations were made of the open clusters M35 and NGC 2158 during theinitial K2 campaign (C0). Reducing these data to high-precision photometrictime-series is challenging due to the wide point spread function (PSF) and theblending of stellar light in such dense regions. We developed animage-subtraction-based K2 reduction pipeline that is applicable to bothcrowded and sparse stellar fields. We applied our pipeline to the data-rich C0K2 super-stamp, containing the two open clusters, as well as to the neighboringpostage stamps. In this paper, we present our image subtraction reductionpipeline and demonstrate that this technique achieves ultra-high photometricprecision for sources in the C0 super-stamp. We extract the raw light curves of3960 stars taken from the UCAC4 and EPIC catalogs and de-trend them forsystematic effects. We compare our photometric results with the priorreductions published in the literature. For detrended, TFA-corrected sources inthe 12--12.25 $\rm K_{p}$ magnitude range, we achieve a best 6.5 hour windowrunning rms of 35 ppm falling to 100 ppm for fainter stars in the 14--14.25 $\rm K_{p}$ magnitude range. For stars with $\rm K_{p}> 14$, our detrended and6.5 hour binned light curves achieve the highest photometric precision.Moreover, all our TFA-corrected sources have higher precision on all timescales investigated. This work represents the first published image subtractionanalysis of a K2 super-stamp. This method will be particularly useful foranalyzing the Galactic bulge observations carried out during K2 campaign 9. Theraw light curves and the final results of our detrending processes are publiclyavailable at \url{http://k2.hatsurveys.org/archive/}.

Image Subtraction Reduction of Open Clusters M35 & NGC 2158 In The K2 Campaign-0 Super-Stamp