Samuel Oschin telescope

It originally used 10 in and 14 in glass photographic plates. Since the focal plane is curved, these plates had to be preformed in a special jig before being loaded into the camera. Construction on the Schmidt telescope began in 1939 and it was completed in 1948. It was named the Samuel Oschin telescope in 1986. Before that it was just called the 48 in Schmidt. In the mid-1980s, the corrector plate was replaced using glass with less chromatic aberration, producing higher quality images over a broader spectrum. Between 2000 and 2001, it was converted to use a CCD imager. The corrector plate was recently replaced using glass that is transparent to a wider range of wavelengths. The telescope was originally hand-guided through one of two 10 in refracting telescopes mounted on either side. The camera is now fully automated and remote-controlled. The data collected are transmitted over the High Performance Wireless Research and Education Network (HPWREN). It is programmed and operated primarily from Pasadena, California, with no operator on site, except to open and close the observatory dome.

• Location — San Diego County, California, United States • Observatory — Palomar Observatory

The first CCD camera installed was the Near-Earth Asteroid Tracking (NEAT) camera, which had three separate 4k×4k sensors arranged in a north–south line with substantial (1°) gaps between them. The total field of view was 3.75 square degrees. From 2003 to 2007, it was the home of the Quasar Equatorial Survey Team camera. This consisted of 112 CCDs, each 2400×600 pixels (161 megapixels total), arranged in four columns of 28 (with gaps between), the largest CCD mosaic used in an astronomical camera at the time. The next camera installed (in 2009) was a 12,288-by-8,192-pixel mosaic (100 megapixel) originally built for the Canada–France–Hawaii Telescope. This had a field of view of 7.8 square degrees, and was used for the Palomar Transient Factory. In 2017 the telescope became the host of the Zwicky Transient Facility. Unlike its predecessors, this was custom designed for the Oschin telescope and its wide field of view, using a 16×6144×6160 CCD array (606 megapixels) with a 47-square-degree field of view.

The Oschin Telescope was responsible for the discovery of 90377 Sedna on 2003-11-14 and Eris, the "10th Planet" on 2005-01-05 from images taken 2003-10-21. The peculiar Type Ia supernova SN 2002cx was discovered with the Oschin telescope on 2002-05-12, 21 UT. Other discoveries include 90482 Orcus (in 2004) and 50000 Quaoar (in 2002), both large trans-Neptune objects. In June 2011 it was reported the telescope discovered 6 supernovae located 8 billion light years from Earth whose composition lacks hydrogen. This is different from normal supernovae, and will contribute to the research of star formation.