About the ASAS-SN CV Patrol


ASAS-SN CV Patrol's Purpose

Alpha Release

We are currently adding more features to this website. While we plan to make our photometry for the CVs available in csv format in the future, we have now made our "Active CVs" public to aid observers in identifying which targets are likely active.


Even in the modern era, only human eyes scan the entire optical sky for the violent, variable, and transient events that shape our universe. The All-Sky Automated Survey for Supernovae (ASAS-SN or "Assassin") is changing this by monitoring the extra-galactic sky down to V~17 mag every 2-3 days using multiple telescopes hosted by Las Cumbres Observatory Global Telescope Network LCOGT, in both the Northern and Southern hemispheres.

Cataclysmic Variables are by far the most common events observed by ASAS-SN. This webpage is dedicated to these Galactic transients. Since April 2013 ASAS-SN has identified hundreds of new cataclysmic variable stars in addition to monitoring new outbursts of known variables. To make our real-time data available to the CV community, we have launched this automated CV Patrol. It is a long term goal of ASAS-SN to make all our data public in real-time, and this patrol will serve as a framework for future ASAS-SN data releases.

Details and Methodology:

We utilize the AAVSO catalog and the ASAS-SN Transients webpage to obtain our CV targets. As we monitor the sky, we perform aperture photometry at the locations of known CVs and compare the resulting magnitudes to those of our reference images. Outbursts within the last week that are one or more magnitudes brighter than their reference fluxes are automatically flagged and sent to this website, after a check for asteroids has been performed. We continue to list the CV as long as it remains one magnitude above the reference flux. New CV Candidates also appear after they are first made public on the ASAS-SN transients webpage. Red text in the outburst column of the Active CVs table indicates a brightening of the source after the initial discovery.

About Us

The ASAS-SN group members who led this project are Bianca Davis, Bart Shappee, Ben Shappee and Kris Stanek.

Support and Collaborators

We thank LCOGT, the NSF and The Center for Cosmology and Astro-Particle Physics (CCAPP) for their support of ASAS-SN and the ASAS-SN CV Patrol.

How to contribute If you have questions/comments, please write to us as at: davis.4811 AT osu DOT edu

Thank you!

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