Located in Dome B
Aperture 910mm, 4.57m focal length, f/15
The Yapp 36-inch reflecting telescope situated in Dome B is open to the public during the day. Learn more about it on one of our telescope tours.
Built in 1932 by Grubb Parsons of Newcastle-upon Tyne at a cost of about £15,000 (including the dome), the 36-inch reflector was a
gift from Mr William Yapp, a prominent industrialist. The telescope was moved to Herstmonceux in 1958 after 21 years of service in Greenwich, where it had been the largest working telescope.
There is a large concave mirror – the primary mirror – at the bottom of the telescope, facing upwards. Light from the stars falls onto this large mirror and is bounced back up the tube where a smaller mirror near the top reflects this light back through the a hole in the centre of the main mirror. The primary mirror aperture measures 91cm with a focal length of 4.6m and a cassegrain focus of f/15.
This telescope was used for astronomical research – mainly stellar spectroscopy and photometry – and later as a test bed for equipment developed for use elsewhere, particularly the Isaac Newton telescope, installed at Herstmonceux in 1967. Astronomers used this telescope mainly to find out about individual stars.
Read more about our telescopes…
