Three-reflections telescope proposal as flat-field anastigmat for wide field observations at Dome C

¹ Observatoire Astronomique de Marseille Provence, LAM - 2, place Leverrier, 13248 Marseille Cedex 4, France
² Istituto di Astrofisica Spaziale e Fisica Cosmica, via Fosso del Cavaliere 100, 00133 Roma, Italy
³ Observatoire Astronomique de Marseille Provence, OHP, 04870 St. Michel l'Observatoire, France

Abstract

It is now evident that the exceptional seeing at Dome C will allow, in the next years, to pursue astronomical programs with conditions better than at any other observatory in the world, and very close to space experiments. Considering a new type of wide-field telescope, particular astronomical programs could be well optimized for observations at Dome C such as surveys for the discovery and follow up of near-Earth asteroids, search for extra-solar planets using transit or micro-lensing events, and stellar luminosity variations. We propose to build a 1.5–2 m class three-reflections telescope, with 1–1.5 degree FOV, four times shorter than an equivalent Schmidt telescope, and providing a flat field without requiring a triplet- or quadruplet-lens corrector since its design is anastigmatic. We present the preliminary optical tests of such designs: MINITRUST 1 and 2 are two 45 cm identical prototypes based in France and Italy, and manufactured using active optics techniques.