Telescopes

The Astrophysics department at Radboud University has two optical telescopes and a radio interferometer with two radio dishes. The optical telescopes are installed in two domes on the southern wing of the Huygens building, one hosting a historical refractor, the other a modern catadioptric.

For whom?

The telescopes are accessible to a broad range of users, encompassing students, astronomers, and proficient amateur observers. They support educational activities, advance scientific projects, and are open for use by trained enthusiasts during scheduled observing nights.

RRL Optical telescope

Optical telescopes

The refractor is 20 cm in diameter and has a focal distance of 208 cm (f/ 10.4). The objective lens is a Littrow doublet, composed of an equiconvex crown glass lens and a second flint glass lens. It is mounted in a commercial equatorial mount Micron GM4000, that can be operated from the manual control and the computer. Also mounted in the same platform there are a finder (a 6 cm-diameter refractor with a focal length of 70 cm, f/11.6, giving a field of view of 130 arcmin with current eyepiece) and an astrograph (14 cm-diameter and focal length 70 cm, f/5).

It is a very special, priceless telescope. The tube and the focusing device, as well as the finder, were built in 1905 by Maurice Manent, and the main lens was built and tested by Dr. André Couder in 1932. It is older than the Waalbrug, the arch bridge over the Waal river inaugurated in 1936, that has become one of the identity signs of the city of Nijmegen. Over a hundred years old, everything is in perfect condition and fully operational. We use the telescope for solar projection observations, public observations and astrophotography.

The catadioptric telescope is a 14-inch (35.6 cm) diameter Schmidt-Cassegrain with 3.56-m focal distance (f/10), a Meade LX200GPS model. It includes a finder with 53 mm-diameter and 8x magnification. It is also mounted in a commercial equatorial mount Micron GM4000, that can be operated from the manual control and the computer. We have a few eyepieces that provide fields of view in the range 12-33 arcmin. We also have a CCD camera with a wheel of filters, model SBIG-ST-10XME, and a 2184×1472 pix (3.2 Mpix) detector covering a ~15×10 arcmin field of view. We use this telescope to teach students how to work with CCD cameras, and for a few science projects. An auto-guiding camera and a motor focuser have been installed on the telescope, enhancing its capabilities for conducting scientific observations.

Radio telescope

Radio telescopes

The department owns its own radio telescope, a 2-element radio interferometer, which is located on the roof of the Huygens building. This makes the Radboud University the only university in the Netherlands with their own radio interferometer. The Radio Interferometer (RIF) consists of two 3.5-m dishes and is used for teaching and student projects. On completion of the refurbishment of the RIF in 2021, it was renamed the Ulrich J. Schwarz Radio Interferometer. Schwarz moved from his native Switzerland to the Netherlands to be involved in the first generation of radio telescopes in The Netherlands, and became guardian of the RIF at Radboud University after his retirement. 

Telescope access for amateurs

If you are an experienced observer, and you have received the specific training to operate the telescopes, you can book observing nights for the two telescopes:

Contact and access

For more information about the telescopes or about upcoming training sessions to learn how to operate these telescopes, please get in touch with the Outreach team of the Astrophysics department.

Contact department