UPDATE: The JKT was in use by the ING observing community from 1984 until July 2003. Over the next decade, it remained part of ING and was in occasional use for various projects (e.g. SCIDAR characterisation of atmospheric turbulence above the observatory).
As of 15 Jan 2014 the JKT is owned by the Instituto de Astrofísica de Canarias (IAC), and is operated by the Southeastern Association for Research in Astronomy (SARA) in the USA and has been fitted out with a new telescope control system (TCS) and camera. The JKT resumed operations as a robotic telescope in October 2015. See Press release for more info.
In my time, the JKT was used almost exclusively with the f/15 optics. The only time the f/8 optics were fitted was when using the wide field photographic plate camera. As the JKT now forms a part of the SARA network and the existing telescopes are fixed at using an f/8 focal ratio (or close to) - To maintain a similar field of view, the f/8 option was the natural choice for the re-commissioned telescope.
The JKT is a versatile telescope in that it can work at f/15 as a classical Cassegrain or at f/8 (the Harmer-Wynne system) producing a highly corrected flat focal plane of 90 arc-minutes diameter suitable for astrographic work.
Over the years, the JKT produced some excellent science, but due to financial cutbacks the JKT is no longer supported by the ING. The last observations with the common user CCD camera were made in August 2003. However, I was pleasantly surprised when asked if I would like come out of retirement to re-commission the telescope in February 2004. The telescope was requested for use by the Instituto de Astrofisica de Canarias (IAC) for a long term observing program using their SCIDAR instrument for the measurement of atmospheric turbulence. This I did and after fixing some minor faults, the JKT to the best of my knowledge has been working well ever since.
Photo of me in the JKT probably taken sometime in the late 1980's. It must have been in the winter seeing my attire! The instrument fitted below the general purpose 'Ellis A&G box' is the Peoples' Photometer which I was responsible for maintaining. A troublesome instrument at times!
The JKT had a far greater suite of common user instruments than the other ING telescopes when it was in regular use. These being:
Occasionally, there were visiting university instruments attached also: The Hatfield Photometer, the Leicester Photometer and the Durham Polarimeter are some that I remember.
In later years with the need to cutback on maintenance support, only the JAG was offered which I looked after until I retired. I could go up there today and still remember how to cable up and test out the JAG or the PP as I done it so many times!
I enjoyed working with the JKT; probably more so than on the larger telescopes. Sometimes there were nights allocated for engineering work and when this was done, I became an astronomer for the rest of the night taking images for PR use. A most enjoyable experience.
The year 2009 was declared as the International Year of Astronomy This being the 400th anniversary of when Galileo made his amazing astronomical discoveries after making his own telescope shortly after its invention in 1608. The year 2009 was also important as being the 40th anniversary of the Apollo 11 moon landing on the 20th July 1969.
The ING participated during the IYA and on the 3rd April 2009 the WHT featured in the webcast Around the World in 80 Telescopes - I'm sitting at the control desk with my back to the camera 'trying' to look busy! The archived video can be seen here which also includes visits to some of the other telescopes at the ORM including the 10.4 metre GTC.
During this time, the ING hosted a group of students and their teacher from Marlborough College in the UK who were given the opportunity to observe visually using the JKT and partake in the IYA Moonwatch week. However, because of the SCIDAR instrument being fitted to the telescope, they could only observe through the finder. A 200mm f/16 refractor.
The lens is open to the sky and to the best of my knowledge had never been cleaned since the telescope was commissioned in 1984. Also the rack and pinion focuser had seized up due to lack of use and I took that away and repaired it. We decided to clean the lens a few days before the students observed through the finder and the photos below show the before and after results. Quite a difference!
The students had a great time at the JKT. Some making sketches of the lunar surface and later observing southern nebulae and star clusters not seen from their college observatory in the UK. A memorable night for all of us.
Photo credits: Javier Mendez (ING)