K2 Campaign 4 data release

News article posted on by Knicole Colon

Target pixel files, light curves, and full frame images for Campaign 4 are available for download from the K2 data archive at MAST. In Campaign 4, 15,853 long cadence and 122 short cadence targets were observed. Additionally, large circular pixel masks were collected that cover bright 3-5 mag B-stars and red giants in the Hyades and Pleiades open clusters. Data for these nine stars are listed by custom aperture number at MAST, rather than by EPIC number. A Trans-Neptunian Object (2002 KY14) was also observed, and 1340 pixel masks were collected to cover the trajectory of this moving target.

Data release notes for Campaign 4 are available on this website. Users are encouraged to read the release notes in full and note in particular the following:

  • Due to the dust clouds near the Pleiades, the background removal near the cluster has larger than normal residuals.
  • There are 887 stellar targets that have light curves with more noise than expected, as they were likely created with non-optimal apertures. This is due to incompatibility between K2 roll motion and determination of photometric optimal apertures.
  • A fraction (23.8%) of stellar targets have light curves generated from apertures that are larger than optimal because they have lower than expected flux compared to their Kepler magnitudes in the EPIC.
  • A different group of stars have higher than expected flux, also resulting in non-optimal apertures.