GTC - M3 Tower

Gran Telescopio Canarias
 M3 Tower


rnThe GTC telescope is a Spanish telescope with a segmented primaryrnmirror of 10 m installed in the Canaria Islands ( La Palma). The M3rntower is used to hold the M3 unit in cantilever at 45°and is fixed inrnthe centre of the M1 mirror cell. The M3 mirror must be movable tornpoint either on one of the 2  Nasmyth directions or to one of thern4 folded Cassegrain foci. The M3 mirror must also be removed from therncentral field to allow light going through the telescope Cassegrainrnfocus. All these functions must be done inside the M3 tower.

rnThe M3 tower includes a steel structure of about 4 m height and lessrnthan 2 m diameter supporting the rotation bearing and its motorizationrnbut also the 2 motorized linear guide tables allowing to remove the M3rnunit form the central field. This part do also the connection with thernM1 cell. The upper part is a lightweight aluminium structure ( < 100rnkg) of about 3 m height used as a baffle for the M3 mirror. Thernrepeatability of the positioning in rotation on Nasmyth or FoldedrnCassegrain foci is better than 15 mrad. The repeatability of thernlocking of the M3 unit at 45° is better than 7 mrad in tilt and 10 mmrnin axial position.

Customer: Gran Telesccopio Canarias (10m) – SPAIN

[2007-04-16]