VizieR Online Data Catalog: The GTC OSIRIS broad-band DR1 (Cortes-Contreras+, 2020)

We obtain 27470 raw broad-band images from the GTC Public Archive acquired between 2009 April and 2014 January in the griz bands. A total of 5638 among them were obtained using windowing (moving target images) and were discarded for the present release. The vast majority of them were targeting a few transiting targets requiring a high temporal frequency, and the loss in spatial coverage is minimum. Thus, it is important to remark that the absence of a source in the catalogue does not imply the absence of GTC OSIRIS observations in that position of the sky.

A significant number (13230) of early images were missing the standard MJD-OBS keyword giving the precise acquisition date, which is crucial for many studies focusing on the time-domain. Although it is possible to recover the missing information through other non-standard FITS keywords (e.g. OPENTIME), we will focus in this first data release on the 8602 (27470-5638-13230) images with the standard MJD-OBS keyword. Among them, there are 858 calibration images that will not be included in the catalogue. Hence, we process 7744 OSIRIS images in the griz filters.

In this first release, the data base includes 6788 images in the Sloan griz bands with exposure times ranging from 0.5 to 900s, and 6226520 entries in the catalogue corresponding to 633559 astronomical sources. The catalogue is astrometrically and photometrically calibrated in standard PSF and automatic (Kron equivalent) photometry using 2MASS, SDSS DR10, or USNO-B1 for the astrometry and Pan-STARRS DR1 for the photometry, allowing a broad range of scientific activities.

Table C1 lists the OSIRIS and Gaia DR2 identifiers and effective temperatures of the 49 dwarf candidates and the identifiers of the late-type binary components.

(3 data files).