The Evryscopes: observing the entire sky at high cadence (Conference Presentation)

Abstract

The Evryscope is a new type of array telescope which monitors the entire accessible sky in each exposure. One Evryscope has covered the Southern hemisphere from Chile since 2015, and we will soon deploy another Evryscope to cover the North from Mount Laguna Observatory in California. Each telescope, with 692 MPix covering an 8000-square-degree field of view, builds many-year-length, high-cadence light curves for every accessible object brighter than ~16th magnitude. An overlapping 4000-square-degree region between each system will give simultaneous multicolor observations with a 8,500km baseline. Every night, we add more than a billion object detections to our databases, enabling the detection of exoplanet transits, microlensing events, nearby extragalactic transients, gravitational wave electromagnetic counterparts, and a wide range of other short timescale events. The Evryscopes are designed to complement surveys such as TESS, providing multi-color context, longer-term observations and higher cadence across the sky. Although the Evryscope telescopes are small, they integrate for more than 6 hours on each part of the sky each night, enabling the system to form high-cadence counterparts to surveys such as LSST. All data, over 600Gb per night, is recorded for realtime analysis. Co-adding achieves depths of g>17 each hour across the entire accessible sky, and our on-site pipelines add all object detections to our databases in realtime. I will discuss the system design, including building the telescopes for fully-robotic operation, actuating our lens-camera interface at few-micron precisions to optimize our image quality, and the big-data analysis required to explore the petabyte-scale dataset we are collecting over the next few years. I will also present the first results from the Southern Evryscope.