Time-Domain Sky Surveys: Current Practice and Future Needs
Thomas A. Prince

Jet Propulsion Laboratory
California Institute of Technology

Abstract. 

Time-domain astronomical surveys are playing an increasingly
important role in astronomy, driven by the availability of large format
digital sensors and powerful computational resources. Examples of
such surveys include the Palomar Transient Factory (PTF), the Catalina
Real-time Transient Survey (CRTS), the PanSTARRS survey, and the
future Large Synoptic Survey Telescope (LSST) and Zwicky Transient
Facility (ZTF). These surveys typically are sensitive to on order of a
billion or more objects over the course of a year and the challenge is to
find the few hundred to a few thousand most interesting variable sources
among the total collection of objects. These include supernovae, gammaray
bursts, near-earth asteroids, cataclysmic variables, and a large number
of other exotic objects. While technical challenges exist in the area
of database management and storage, the most difficult challenges are
algorithmic. We will discuss some of the principal challenges, including
the unique problems associated with the intrinsically heterogeneous
collection of time-domain data and the application of machine learning
techniques to automatic identification of interesting variable sources.