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Mission Overview

Kepler Increased Resolution Image Subtraction ("IRIS")


Primary Investigator: Isabel L. Colman

HLSP AuthorsIsabel L. Colman, Timothy R. Bedding, Daniel Huber, and Hans Kjeldsen

Released: 2021-12-13

Updated: 2021-12-13

Primary Reference(s): Colman et al. 2021

DOI: 10.17909/t9-w8fw-4r14

Citations: See ADS Statistics

Read Me

Stitched and corrected light curve
Top panel: Stitched and corrected light curve for KIC 2437745, a probable member of NGC 6791. Middle panel: close-up of Quarter 9. Bottom panel: Amplitude spectrum calculated using all 17 quarters of data. Figure from Colman et al. 2021.


The open clusters NGC 6791 and NGC 6819 both lay in the Kepler mission's field of view — however, due to crowding, the majority of stars in and around the clusters were not individually targeted for long or short cadence photometry during the mission. Instead, both clusters were targeted with 200x200 target pixel files, known as "superstamps." The team presents long cadence light curves for all 9,150 KIC targets that fall on the superstamps, including cluster members and field stars. This data release includes light curves for 8,427 new targets with no previously available photometry, and an extended time series baseline for 382 long cadence targets.

The team produced these light curves using an image subtraction photometry pipeline, described in Colman et al. 2021, which is optimized for variability and reducing noise on crowded targets. There are at most 17 quarters (1--17) of photometry available for NGC 6791, and 14 (1–5, 7–9, 11–13, 15–17) for NGC 6819. Due to detector drift between seasons, targets towards the edges of the superstamps may not have all quarters available.

Data Products

The single-quarter light curve files have the following naming convention:



  • <kcid> = the 9-digit, zero-padded Kepler Input Catalog (KIC) ID.
  • <quarter> = the 2-digit, zero-padded Kepler quarter ID (e.g., "04" for Quarter 4).

The stitched light curve files have the following naming convention:



  • <kicid> = the 9-digit, zero-padded KIC ID.

The files are organized into subdirectories based on the following path structure:



  • <mmmm> = the first four digits of the zero-padded KIC ID.
  • <kicid> = the 9-digit, zero-padded KIC ID.

Data file types:

_lc.fits The single-quarter or stitched Kepler light curve file.

Data Access

IRIS light curves are available in the MAST Portal (web-based, cross-mission search interface) and Astroquery (Python package to search for and download files from Python scripts you write).  For those who want to download all IRIS light curves for a given Quarter, or all stitched light curves, we provide bulk download scripts in the table below.

  • A web-based interface for cross-mission searches of data at MAST or the Virtual Observatory. Download IRIS light curves for a few targets.
  • Search for, and retrieve, IRIS data products programmatically based on a list of coordinates or target names.
cURL Script Files By Quarter, stitched (Downloads FITS Files Only)
Stitched Quarter 1 Quarter 2 Quarter 3 Quarter 4 Quarter 5
Quarter 6 Quarter 7 Quarter 8 Quarter 9 Quarter 10 Quarter 11
Quarter 12 Quarter 13 Quarter 14 Quarter 15 Quarter 16 Quarter 17




Please remember to cite the appropriate paper(s) below and the DOI if you use these data in a published work. 

Note: These HLSP data products are licensed for use under CC BY 4.0.