An open optical transient survey

CRTS-II Transients

  • Human Classified OTs
      Archival CSS, MLS and SSS transients
    • Archive
  • Transient Stats
  • Monitored Objects
  • Event follow-up
  • Other Alerts
  • News: Read about Filipp Romanov's discovery of a supernova
    in the CRTS supernova hunt project in Newsweek.

    CRTS-II transient candidates are no longer being processed.

    CRTS Transient Discoveries:

    Image: © Axel Mellinger

    Current Observing Weather: Mt. Lemmon .
    More News: Data Release The Catalina Periodic Variable catalog is available here.
    You can access the extended lightcurves of 500 million sources in CSDR2.

    CRTS FU Ori's. CRTS collaborates with LSST on iPhone event app.
    CACR and UA news, featured in, redorbit, skynightly, spaceref, astronomynow. Article on Catalina discoveries in Forbes. Read about the Catalina data release in Sky and Telescope.

    The Survey


      The Catalina Real-Time Transient Survey is a synoptic astronomical exploration that covers thirty three thousand square degrees of the sky in order discover rare and interesting transient phenomina. The survey utilizes data taken by the three dedicated telescopes of the highly successful Catalina Sky Survey (CSS) NEO project. CRTS detects and openly publishes all transients within minutes of observation so that all astronomers may follow ongoing events.

      Automated Analysis

      CRTS builds on the work performed for the Palomar Quest survey and continues to pave the way for deeper upcoming transient surveys (LSST), by automating the event discovery and classification processes so that robust decisions can enable intelligent human and robotic follow up.

      Rapid Response

      In order to fully understand rapidly varying transient astronomical behaviour, automated alerting and follow-up is a necessity. Rapid transient science is enabled by the affiliated projects VOEventNet and SkyAlert.
      • VOEventNet is a means of transporting astronomical events to interested subscribers, automatically within minutes of discovery.
      • SkyAlert enables users to perform complex queries about discoveries in order to receive personally tailored and filtered event streams.

      CRTS also publishes VOEvents directly to the general public via Google Sky in kml.

      Survey Telescopes


      The three telescopes used by CRTS.

      Open Data

      CRTS has made the entire CSS photometric dataset public as a service to the astronomical community. Images are in the process of being released. Meanwhile requests for images can be made to us directly.

      If you intend to make use CRTS data in a publication, please cite:
      Drake, A.J. et al. First Results from the Catalina Real-time Transient Survey, 2009, ApJ, 696, 870.