Exploration of the Time Domain (Abstract)

Volume 45 number 1 (2017)

George Djorgovski

California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125; george@astro.caltech.edu

Abstract

(Abstract only) Time-domain astronomy is one of the most active and growing areas of astronomical research today, thanks to the new generation of synoptic sky surveys, and leading to LSST. Catalina Real-Time Transient Survey (CRTS; http://crts.caltech.edu) is systematically exploring and characterizing the variable sky since 2008, with the archival data going back to 2005. The survey covers the total area of ~33,000 deg2, down to ~19–21 mag per exposure, with time baselines from 10 min to ~10 years, and growing; there are now typically ~200–400 exposures per pointing, and coadded images reach deeper than ~23 magnitude. The survey has so far detected over 13,000 unique, high-amplitude transients, including ~4,000 confirmed or likely supernovae, nearly 2,000 CVs (the great majority of them previously uncatalogued), about 4,000 blazars and other flaring AGN, and a broad variety of other types of objects. Many of these objects can benefit from a follow-up by the amateur community. CRTS is intended to be a data resource for the entire astronomical community. We have a completely open data policy: all discovered transient events are published in real time with no proprietary delay period, and all data are made public, in order to better serve the entire community, and maximize the scientific returns. This includes an archive of ~500 million light curves, which are being updated continuously. This is an unprecedented data set for the exploration of the time domain, in terms of the area, depth, and temporal coverage. Numerous scientific projects have been enabled by this data stream, including: discoveries of ultraluminous and otherwise peculiar SNe; unusual CVs and dwarf novae; mapping of the structure in the Galactic halo using RR Lyrae; variability-based discovery of AGN and probes of their physics; and so on.