Toward a Continuous Record of the Sky

It is currently feasible to start a continuous digital record of the entiresky sensitive to any visual magnitude brighter than 15 each night. Such arecord could be created with a modest array of small telescopes, whichcollectively generate no more than a few Gigabytes of data daily.Alternatively, a few small telescopes could continually re-point to scan andreco rd the entire sky down to any visual magnitude brighter than 15 with arecurrence epoch of at most a few weeks, again always generating less than oneGigabyte of data each night. These estimates derive from CCD ability andbudgets typical of university research projects. As a prototype, we havedeveloped and are utilizing an inexpensive single-telescope system that obtainsoptical data from about 1500 square degrees. We discuss the general case ofcreating and storing data from a both an epochal survey, where a small numberof telescopes continually scan the sky, and a continuous survey, composed of aconstellation of telescopes dedicated each continually inspect a designatedsection of the sky. We compute specific limitations of canonical surveys invisible light, and estimate that all-sky continuous visual light surveys couldbe sensitive to magnitude 20 in a single night by about 2010. Possiblescientific returns of continuous and epochal sky surveys include continuedmonitoring of most known variable stars, establishing case histories forvariables of future interest, uncovering new forms of stellar variability,discovering the brightest cases of microlensing, discovering new novae andsupernovae, discovering new counterparts to gamma-ray bursts, monitoring knownSolar System objects, discovering new Solar System objects, and discoveringobjects that might strike the Earth.Comment: 38 pages, 9 postscript figures, 2 gif images. Revised and new section added. Accepted to PASP. Source code submitted to ASCL.ne