The MiniMosaic Imager is On-Line at WIYN

Abhijit Saha

The WIYN telescope has a new imager, the MiniMosaic with two SITE 2K x 4K CCDs arranged side by side to provide a 4K x 4K viewing area. At the Nasmyth f/6.3 focus of WIYN, this imager covers an area that is 9.6´ on the side, with pixels that project to 0.14" on the sky, thus providing good spatial sampling in even the 0.4" seeing conditions that are increasingly common at the WIYN telescope. The combination of a relatively large field of view with the excellent images across the entire field produced by this camera (less than 10% change in point-spread function even in 0.4" seeing) in excellent, naturally delivered seeing make the images suitable for stellar photometry in large, faint, crowded fields, which is a targetted goal for the WIYN.

Commissioning activities for the MiniMosaic have been completed, and the instrument has become the default imaging instrument at WIYN. The User's Manual for MiniMosaic is available at http://www.noao.edu/kpno/docs.html .

Caption: An image of the globular cluster M3 (NGC 5272) obtained with the MiniMosaic at WIYN. This 120-second exposure in the `B' passband has stellar images with FWHM of better than 0.5" that are uniform all the way to the corners of the 9.6´ on-a-side image. The insert shows how well the relatively small pixels in MiniMosaic sample the superb image quality obtained at WIYN.