The 1 metre Jacobus Kapteyn Telescope (JKT)

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 JKT building. Photo taken in 1986

This shows the telescope working in the f/8 configuration. This optical system was only used with the Wide Field Photographic Plate Camera which is shown fitted below the mirror cell. To work at f/8, a large spherical secondary mirror was fitted and a corrector doublet lens mounted in the centre box section. A large sky baffle tube was also required and this can be seen in the images. Photos taken in 1986.

Photo taken during the f/8 optics change

The top ring assembly containing the spherical secondary mirror has been fitted along with its large sky baffle tube. The f/15 top end ring (with a protection cover over the mirror) is now waiting to be craned down to the instrument store. The cones around the circumference of the ring ensured the optical alignment remained correct when changing between secondary mirrors, but in practice a collimation check using an alignment telescope when the f/8 optics were fitted was done.

I can still picture 'Wol' balanced on a step ladder with a spanner in his hand tweaking the adjusters of the mirror cell and none too happy when he found after making a measurement that he had turned one in the wrong direction :-)

Looking down the tube with the telescope in the access park (horizontal) position.

The only 'electronics job' needed with this instrument change was to fit the focus drive cables to the connector panel at the top of the truss and later to check out the WFC. A very simple instrument with just a roller blind shutter (that was not unknown to occasionally jam!), a calibration lamp source and a photo-multiplier tube head for the autoguider.

I recall on one occasion the autoguider failed, but this didn't deter ex-RGO astronomer Derek Jones from losing valuable observing time! He continued in the time honoured way of hand guiding the telescope from out in the dome for the rest of the night.

Some images taken of the JKT in 2005 with the SCIDAR instrument fitted. The telescope instrument rack once filled with controllers is now empty. A sad sign of the times! SCIDAR is operated from a PC within the control room via the cable harness shown in the photo to the left.
The JKT control desk and SCIDAR PC terminal. Many of the push buttons are no longer used and panels containing obsolete displays have been removed and the apertures blanked off. The telescope control system (TCS) since 1998 is now handled by a DEC ALPHA computer.
The observers corner of the control room with the SUN workstations formerly used to control the JAG and and acquire images from the CCD camera. Perhaps one day they will be used again...
Added - Me at the JKT some 20 years on from the first photo shown on this page. Photo taken sometime in 2007.

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)

After the heavy dew shield was removed. The finder objective lens showing showing some 25 years of dust accumulation!
Tibor, the ING optics specialist first removed loose dust particles with dry air from a can and then carefully cleaned the lens with lint free pads soaked in Isopropyl Alcohol.
Of course, its always a good time to pose for a photo! Tibor looking happy with the results :-)
The lens after its been cleaned. Not 100% perfect, but a lot better than it was !
After re-fitting the dew shield, me looking at the moon which had just risen enough to clear the dome aperture. As can be seen in the photo, the telescope was very low and it looks like I'm the observing the wind shield, but the moon was just peeking above it!