Gratama Telescope

The observatory has a 40 cm reflector telescope and is of the Ritchey-Chrétien type. It is one of the largest telescopes in the Netherlands. The telescope has got high quality optics and is ideal for photographing objects deep in the Universe. The telescope is simply just a smaller version of the large professional telescopes that stand on remote mountain peaks, making great discoveries. The telescope is named after the Gratama stichting. This foundation, founded and established in Harlingen, in collaboration with the Groninger Universiteitsfonds has made the acquisition of this scientific instrument possible.

Photography

One of the ways to learn more about outer space is photographing (weak) objects in the Universe. Photographing these objects is not as easy as just taking a picture with a normal camera. A very sensitive digital camera is used and has to be cooled down in order to reduce noise on the recordings. The digital camera is sensitive to all colours of light and is therefore a kind of black and white camera. Recording showing different colours are constructed using and combining different images taken with different filters. A filter is a thin glass disc that only transmits a colour of light. In the camera of the Gratama telescope there are 8 filters built in for 8 colours that astronomers find interesting.

Spectroscopy

Photography is not the only way to learn more about the Universe. Spectroscopy is perhaps just as important. For example, with this technique it has been proven that the Universe is expanding and from which substances stars exist. In spectroscopy you unravel the light in the colours of the rainbow and study the light in all these different colours. Colours that are missing provide a lot of interesting information. To get this information, the Blaauw Observatory also has got a spectrograph. This optical system is located in a small room right under the dome. The light from the stars collected by the telescope is led to this room via a fiber optic cable. Students can conduct research with the spectrograph and thus learn everything about the universe.

See for yourself!

Scientific research after the observation is very interesting, but looking through a stargazer yourself is really beautiful. To look through a telescope an eyepiece must be placed in the back of the telescope. This eyepiece is made of a number of small lenses placed behind each other. You will see a sharply enlarged image of the object on the sky. Since you need a separate eyepiece for each magnification, the observatory has several eyepieces.