Evryscope-South Survey of Upper- and Pre-main Sequence Solar Neighborhood Stars

Using photometric data collected by Evryscope-South, we search for nearby young variable systems on the upper main sequence and pre-main sequence. The Evryscopes are all-sky high-cadence telescope arrays operating in the Northern and Southern hemispheres. We base our search on a Gaia-selected catalog of young neighborhood upper- and pre-main sequence stars which were chosen through both astrometric and photometric criteria. We analyze 44,971 Evryscope-South light curves in search of variability. We recover 615 variables, with 378 previously known, and 237 new discoveries including 84 young eclipsing binaries (EB) candidates. We discover a new highly-eccentric close binary system and recover a further four previously known systems, with periods ranging from 299-674 hours. We find 158 long-period (> 50 hours) candidate EB systems, 9 from the pre-main-sequence and 149 from the upper main sequence, which will allow constraints on the mass/radius/age relation. These long-period EBs include a 179.3 hour pre-main sequence system and a 867.8 hour system from the upper main sequence. For pre-main sequence variable candidates we estimate system ages, which range from 1 to 23 Myr for non-EBs and from 2 to 17 Myr for EBs. Other non-EB discoveries that show intrinsic variability will allow relationships between stellar rotation rates, ages, activity, and mass to be characterized.