Telescope Overview

The Danish telescope was built by Grubb-Parsons, and has been in use at La Silla since 1979. The telescope has an off-axis mount and the optics are of a Ritchey-Chretien design. On account of the telescope's mount and the limited space inside the dome, the telescope has significant pointing restrictions. The telescope is at a geographical location of 70°44'7"662W 29°15'14"235S and an altitude of 2340 metres.

An instrument adaptor is mounted below the mirror cell, and below this is the FASU (Filter And Shutter Unit). The adaptor provides facilities for autoguiding while additional filters can be mounted in the converging beam in FASU. The DFOSC is mounted below the FASU and is the only instrument currently in use.

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DFOSC Overview

The Danish Faint Object Spectrograph and Camera (DFOSC) is a focal reducer type spectrograph/camera similar in concept and in layout to ESO's EFOSC1 and EFOSC2. DFOSC consists of a collimator and a camera, between which are placed a filter and grism wheel. An aperture wheel is situated at the telescope focus. All wheels have 8 positions. The instrument offers the possibility to change between direct imaging and spectroscopy in less than a minute. The spectroscopic mode offers resolutions from about 1-20A for a 1" slit.

As with other focal reducer type instruments, DFOSC is affected by sky concentration, and so it is not recommended that DFOSC be used for photometry where high precision is imperative.

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Information for Observers

DFOSC/Telescope information for observers:

General information for observers:

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DK1.54-m and DFOSC: Technical Information

The below pages concern the telescope and instrument operation, and are mainly of interest to 2p2 Team members.