Fermi and Pan-STARRS 1 (PS1) provide simultaneous overlapping coverage on 75% of the sky (3π steradians, or 100% of the sky north of Dec. = -30 deg.), in gamma-rays and visible-NIR respectively. PS1 uses a 1.8m telescope at Haleakala, Maui, operated by the Institute for Astronomy, University of Hawaii. A 2009 Memorandum of Agreement provides for simultaneous analysis by members of the Fermi Collaboration and PS1 Science Consortium. During 2010-2012 Pan-STARRS achieved sustained performance, accumulating ~500 images per night at 1.4 Gpixel/image, each image covering 8 square degrees.
Observations occur in an optimized sequence using five filters, g, r, i, z, and y, collectively covering wavelengths 405 to 1020 nm. Single exposures reach approximately magnitude 22 in any filter and stacked images go deeper but lose time resolution. Images are analyzed and results distributed using a two-stage pipeline. All 3π steradians have been observed and processed through the first pipeline stage. A substantial sky fraction is also now available from the second stage, which facilitates selective distribution. All PS1 sky coverage is effectively simultaneous with Fermi to within hours at worst.
User feedback has steadily improved photometry, astrometry, and rejection of false positive detections, leading to reprocessing to incorporate improvements. Sky coverage, timescale coverage, filter sequencing, quality of photometry and astrometry are illustrated along with characterization of the overlap and compatibility with Fermi. Blazars and AGN are the largest, but not the only, source category benefitting from access in both instruments. Future observing plans and opportunities for galactic and extragalactic studies are described.