South West Herts
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Visit to Mill Hill Observatory - 2007

On Saturday February 10th 24 of our members had a very enjoyable visit to the Mill Hill Observatory. This is the observatory of London University, and is the best-equipped teaching observatory in the UK. We were led on our tour by the director Mike Dworetsky and two very knowledgeable students, Mckenzie and Deborah.

Mike explained to us that even though the observatory is located close to a busy main road, excellent insulation in the construction of the buildings and first-class and efficient down-lit street lights installed with the cooperation of the council make it a good observing site. The telescopes themselves are mounted on pedestals anchored to the bedrock, making them virtually immune to traffic vibration.

{Click on any image to see a larger version}
The 8 inch Fry Refractor

 

 

 

We first visited the telescopes of the Southern Group, housed in a triple-domed observatory building. The main telescope here was the superb 8" Fry refractor, named after the benefactor who donated the instrument to Mill Hill in 1930. This F15.75 telescope was made by Thomas Cooke and Sons in 1862, and is very accurately polar-aligned (within one second of arc). It has a weight-driven RA drive, and can be equipped with a video camera using a 250-frame integrating software to display the image on a video screen. The instrument is particularly well suited to planetary and solar viewing.


Another view of the Fry Refactor

Click here to see a 'vertical' image

 

We also looked at the Celestron C14, linked to a go-to system using the Software Bisque planetarium software. The eyepiece mount can be switched between regular eyepieces, a CCD camera or a TV camera, and another CCD is used for guiding. A separate web-cam is used to monitor the position of the dome slot, to ensure that it is correctly aligned with the telescope. The third instrument in the triple dome is a 10" Meade.
The 14 inch Celestron Scmidt Cassegrain

The 18 and 24 inch Radcliffe Refractors
We then moved to the dome housing the magnificent twin telescopes of the Radcliffe refractor (24" and 18"). The instrument dates from 1901, and was equipped with a computerized control system in 1991. The telescope is manually moved to the vicinity of the object to be observed, and shaft-encoders are used to inform the computer of the current telescope coordinates. Slow-motion drives then centre the object of interest. This system was of particular interest to us, in relation to our own (rather more modest!) plans to upgrade the drive of our own 14" telescope.

Another view of the Radcliffe telescopes

The Allen Reflector
The original instrument in the last dome to be visited belonged to the pioneering astro-photographer Edward Wilson, and was donated to the University of London for the founding of the Mill Hill observatory. The present 24" Allen reflector is a Richley-Chretien instrument by Ealing Beck, on a German mount. This is a Cassegrain reflector, with no corrector plate, and is fitted with a spectrograph and CCD allowing quantitative study of planets, stars and nebulae (for analysis of elemental composition, radial velocities and rotation rates).

Altogether a thoroughly enjoyable evening, and some of us may even be tempted to enrol on the evening classes on astronomy run by UCL, if only to have the privelege of using some of the instruments at Mill Hill!

Text by Graham Marett, images by Alan Swan & Pat Walker.
Note: When viewing the images in Windows Explorer, you should find a 'zoom button' in the lower right corner of the screen, clicking on this will enlarge the image.

Open evening - 2005

On the 1st of October the Society held an open evening at the High Top observatory for members and friends.

Although poor weather had been forecast it turned out to be a dry and mild evening, and about twenty five people came along to visit our facilities and enjoy this social occasion. We were delighted to welcome a number of our friends and neighbours from Flaunden, who regularly pass our site on the outside and welcomed the chance to see what goes on inside.

We were not able to do any actual observing due to the cloud cover, but we were able to show off our 14” telescope and explain its workings to new members and visitors. We also enjoyed wine and refreshments, kindly provided by committee members.

The Partial Solar Eclipse - 2005

On the 3rd October, a number of members, friends and family met at the High Top Observatory hoping to catch a glimpse of the Partial Solar Eclipse. Unfortunately the weather wasn't too helpful and the fairly intense cloud cover prevented any view of the event. However, the visit did enable a couple of new members to see the observatory.

Some hopeful watchers
But where's the Sun - it's there, no it's there isn't it?

Events and activities - 2004

On a very hot Tuesday 8th June, several members and guests met at High Top observatory to view the transit of Venus - the day could not have been better, with hardly a cloud in the sky!


Some of the assembled members
Photo by Graham Marett


The transit in its last stages
Photo by Richard Westwood

Open evening - 2004

On Saturday September 18th the Society held an open evening at High Top for members and friends. The event was a great success, with about 30 visitors enjoying fine views of the sky and refreshments kindly provided by committee members.

After an unpromising wet afternoon the sky cleared early in the evening, and we had fine views of the 4-day old Moon setting at 8.30 pm. After that we enjoyed one of the best observing evenings for some time at High Top, with clear dark skies, mild weather and no wind. The Milky Way was visible high overhead, and sky-watchers were able to see the International Space Station pass overhead, as well as a couple of satellites and a fleeting meteor.

Bob Garner and Don Doherty manned the 14" telescope, and were able to show visitors fine views of a number of deep-sky objects. These included the 'Great Nebula in Andromeda', which is actually our close galactic neighbour the Andromeda Galaxy (M31, at a mere 2.3 million light years), together with its satellite galaxies M32 and NGC 110. Also on show was the 'Wild Duck' cluster (M11) in the constellation Scutum, a small but extremely rich open cluster containing well over 600 stars. It was given its nickname by the English astronomer Smyth, who likened it to a flight of wild ducks.

We are grateful to all those who helped to make the evening a great success. Special thanks to Hilary Doherty, who looked after the refreshments for us.