Grove Creek Observatory's Telescopes & Equipment:

We purchase and highly recommend products from www.myastroshop.com.au
"Committed to Australian Amateur Astronomy and great service..."

                      Short Summary of Telescopes at Grove Creek:

THE CELESTRON C-14 SCHMIDT CASSEGRAIN:

Celestron Pacific C14 Schmidt Cassegrain Telescope
Aperture: 36cm (14")  Focal Length: 3,910mm  Focal Ratio: f/11
A very unique telescope with somewhat of a unique history....

Watch our video about our C14

Viewing through the C14 Telescope:

Light Path through a Schmidt Cassegrain Telescope

Housed in our main motorised 3.2 meter (10 foot) dome, is our massive Celestron C14. This is our main viewing instrument and with a focal length of 3,910mm (154"), this telescope is used for high resolution objects. Being a Schmidt Cassegrain, it provides a higher contrast than even larger Newtonian telescopes. The C14 was built in 1971 and was the second model made by the "Celestron Pacific" telescope company, using the original sturdy "sand-cast" rigid fork. Its 36cm (14") primary mirror is of an exceptional high optical standard - going beyond testing equipment that could measure an accuracy of 1/10 wavelength of light. The C14 can operate visually at f/11 or f/7 and can be configured with huge a variety of combinations for different types of astrophotography and piggy backed telescopes, with its Losmandy dovetail system. We have the best available eyepieces - including a full range of Tele Vue Naglars and a huge range of adaptors for astrophotography, rear-cell remote focusing and CCD imaging for this instrument. The telescope pier itself, is driven 6 metres (19.5 ft) into the ground and is totally isolated with no part of the building touching it and is 1metre (3.2 ft) in diameter and constructed with a solid steel core, filled with concrete, sealed with a large gas pipe on the outside. The mount's wedge is home made out of 2cm (3/4") thick stainless steel, that makes the C14 very stable. The C14 at Grove Creek has its own fame, as many live astronomical events were recorded with special video cameras attached, including live images of the Shoemaker-Levy Comet hitting Jupiter, that were shown throughout the world on Australian and international TV, including CNN, and the BBC, in July 1994. Well over 10,000 people viewed Halley's Comet through this telescope when it was installed at Grove Creek in 1985.

In 1998, extensive upgrades were made to replace the old original Right Ascension AC clock tracking and DC slewing motor (abbrev. "RA" - the east/west movement) and the DC Declination motor (abbrev. "DEC" - the north/south movement) with a home made Z-80 processor controlled stepping motor control system, designed and built by electronics expert Chris Ralph and astronomer Steven Williams. Along with proper equatorial alignment of the telescope mount, the "timing pulses" of the RA stepping motor is very critical - as the earth rotates from west to east, the telescope has to track the stars as they pass overhead from east to west, otherwise the stars would quickly move out of the field of view and also cause the stars to "trail" in a long exposure photograph. For the first time, on such an old mount, high magnification "auto-guiding" astrophotography and the early days of astronomical CCD imaging was then made possible with this system. Along with the electronic tracking upgrades, a Celestron Astro-Master computerised digital setting circle with encoders, was installed, to make finding objects a breeze. An innovation that  was never even dreamed of, when the mount was designed 30 years ago! Previously, tedious sightings had to be read from old mechanical setting circles attached to the mount.

The new upgrades where very much being enjoyed by both staff and visitors, as it sped up finding objects ten fold - until two disasters struck... In 1999, one of the most severe storms ever seen in the area totally blew the entire 300kgs dome off its rails, driving it into the telescope's mount and destroyed the delicate RA gearing system and mounting hardware for the optical encoders. However, even with such amazing force, the optics of this ruggedly built telescope didn't even loose collimation! Fortunately (and very generously) Celestron, understanding that this particular telescope was of special vintage, re-built the RA gear system at no charge and the dome was modified so such an horrible incident could never happen again. However, to the complete dread of everyone involved with Grove Creek, a violent electrical strike directly hit the C14 in 2002, which not only caused massive damage to most of the electrical devices and appliances throughout the observatory but totally destroyed both the home-made drive controller, Astro-Master and optical encoders!  Parts for the original drive system were no longer available, so it was replaced with a third-party versatile computerised duel stepping motor drive system (which was extensively programmed to work with the unique C14's stepping motors), enabling 7 different speeds to move the telescope, depending on the magnification selected and where the telescope was pointing (as a fork mount is moved further south near the celestial pole, it requires a faster RA speed to slew the telescope.)

The C-14's "brain" - The Argo Navis