Description
The Evryscope is an ultra-wide field monitoring system consisting of over twenty 61mm aperture telescopes that take continuous two-minute exposures with an effective field of view of approximately 8000 square degrees. This ability to take large images at minute timescales makes Evryscope suited for monitoring the early stages of the nearest and brightest transients, such as the post-shock cooling peak following the emergence of the shock breakout (SBO) from the stellar envelope of a core-collapse supernova (CCSNe). However, Evryscope’s limiting magnitude of g = 16.0 and its large pixel size of ≈ 13.5 arcseconds make it difficult or impossible to detect these events if single exposures are used. Stacked images can be used for the detection and photometry of dimmer and extragalactic transients that would otherwise not be detectable on a single exposure. We test the feasibility of combining image frames using Evryscope-South data of the Type IIb supernova SN 2016gkg, and performing photometric measurements for the first week after the initial core collapse. We measure a magnitude of g = 16.79 ± 0.38, within hours of the shock breakout, which agrees within 1σ of predictions from a hydrodynamical SBO code, demonstrating the potential of using Evryscope data to detect and obtain crucial early photometry of supernovae.
