in italiano

MPC 476 Grange Observatory

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The Grange Observatory lies atop a private house in Bussoleno (50 km W from Turin, Italy), in Susa Valley near the French border; Grange comes from the name of the town's suburb.
The observatory's roll-off roof opens in two parts and covers a 3 m by 3 m room; the homemade telescope is a 0.3 m Newton f/3.3 with a focal reducer/planar corrector.
The optical instrumentation is permanently mounted on a concrete pillar and is independent from the room's floor; the observing site can be reached via a foldable ladder from a room devoted to laboratory / library.

The telescope originally had a DOS based SXL-8 CCD camera peltier cooled connected to a 486 DX2 computer with CD-ROM drive, this one being useful for having a quick access to huge star catalogues and sky surveys such as GSC-ACT, Tycho 2 and USNO A2.0: the field given by the cameras was 22x22 arcmin and the faintest stars recorded were about magnitude 17 (15 magn. was reached with 1 minute exposure).
The SXL-8 camera is still used at a 140 mm f/5.7 Vixen astrograph for Johnson B, V, R standard photometry and spectrometry of stars through the ASTROART 5 plug-in working with Windows XP on a ASUS laptop having a parallel port.

For a 30 mas precision astrometry (with URAT-1 catalogue) and ultra-fast photometry with a Gaia G clear filter, a peltier cooled camera QHY6 is mounted at the 300 mm f/3.3 telescope, connected to a Samsung netbook. A basic CYAN color system is also present for transient objects follow-up (consistent with the Gaia DR2 BP band).
The Sony ICX259AL sensor of the QHY6 camera is used at the telescope, giving a 17 x 13 arcmin star field containing asteroids of up to magnitude 19 with 30 s exposures (the 17th magnitude in the GAIA DR1 photometry is reached with a short 15 s exposure).

The main research activity is stellar photometry, although astrometry is still performed being one of the observatories appointed by IAU past Commission 20 which send their measures to the Central Bureau for Astronomical Telegrams/Minor Planet Center, located at Smithsonian Astrophysical Observatory, Cambridge, MA (U.S.A.).
Grange Obs. was also one of the observing sites of Gruppo Italiano Astrometristi, the Italian Astrometry Group, which at the time coordinated all the astrometric activity done in Italy by amateur astronomers, and is a proud member of Spaceguard Foundation.

Currently the privately founded MPC 476 Grange Observatory is making researches on fundamental astronomy, such as astrometry, photometry and spectrometry; the instruments of the observatory can measure the distance, the temperature, the chemical composition of the stars and recently the presence of exoplanets around them.
If interested in the researches and products of the Grange Obs. please have a look of the spin off page.

Technical description:

Go to the AAS homepage, the local amateur association (in Italian).
Return to Grange Obs. homepage.