SkipperCam: a wide-field Skipper-CCD pathfinder for high-cadence imaging with sub-electron capabilities

Abstract

We present SkipperCam, a Skipper-CCD imager pathfinder designed to demonstrate the potential of low-noise, high-cadence wide-field imaging. The pathfinder deploys a 20-sensor Skipper-CCD focal plane (∼27 Mpix) on the 0.6 m Curtis–Schmidt telescope at CTIO, reusing the existing PreCam camera body, shutter, and filter wheel. A massively parallel, MIDNA-based readout architecture decouples the conventional trade-off between low noise and slow readout at the system level, delivering a wide ∼ 2 deg2 field of view with ∼2 s full-frame readout time and ∼ 7 e− readout noise in a fast survey mode, while retaining the ability to reach sub-electron noise through multiple non-destructive sampling. While primarily a technology demonstrator, the instrument is optimized to deliver early scientific results through a dedicated time-domain survey: a high-cadence microlensing survey of the Large Magellanic Cloud targeting short-timescale events from low-mass compact objects, with additional opportunities in fast photometric variability, transient detection, blue-sensitive imaging, and LSST-driven stellar-occultation follow-ups. Beyond its immediate science return, SkipperCam provides the first on-sky demonstration of a multiplexed Skipper-CCD array operating in survey mode. Beyond its own science return, SkipperCam is conceived as a pathfinder for a proposed One Degree Imager (ODI-Skipper) camera that could be installed at the WIYN 3.5 m telescope.