[cpastro] This weeks club meeting Wednesday 20th October 2021

Hi All

This week we had Ted talking about his observatory.

By James Vincent

17 members present and 14 virtually, making 31 in total.

Jim said next week we have a club members observing roundup meeting, participants should contact Jim if they need help with arranging their talk.

Mike introduced Ted for his talk “Teds observatory”

Ted said the great wind of October the 16th 1987 destroyed his greenhouse right next to where he positioned his 6 inch telescope for observing. The greenhouse was the furthest point away from his house and he decided to build an 8 foot observatory in its place. Retrospective planning permission was agreed at the council offices over the telephone but not in writing.

Building started in March 1988 pegs where hammered into the concreate base where the greenhouse had been and the search for hard core began.

Ted travelled to Vacuum coatings at Walthamstow where he looked at a 10 ft Dome and then travelled to BC&F in London to pick up 2 meters of 6 inch dia pipe for a mount for his 6 inch scope.

Ted then had to change the shuttering to make a base for a 10 foot dome in his garden; he said that it’s amazing how much soil comes out of a 1 cubic meter hole.

The dome arrived 6 weeks late and the construction of the observatory was completed in July 1988 first light for the dome was Saturn viewed with his 6 inch telescope due south at 10:30 pm.

Ted decided to upgrade his telescope to a 16 inch f Newtonian reflector in October 1988 this meant doing lots of modifications to the mount and making the slit in the dome wider.

Ted was surprised on his 50th birthday when his wife Eileen presented him with a dome shaped birthday cake and a telescope sticking out of it.

They had been many media events held at the observatory over the years. Ron used the observatory for his experiments with a pinhole camera but that’s another story.

The observatory is still in use today the 16 inch telescope has been sold back to the maker and replaced with a Vixen VMC26L on a Paramount MX mounting.

Ted Finished off his talk by taking questions from the members.

What a fun Night we had.

Club meeting Wednesday 13th October 2021

By James Vincent

Wednesday 13th October 2021

23 members present and 12 virtually, make 35 in total.

Mike opened the meeting and asked if there were any club notices.

Jim said the clubs 12 and 8 inch Dobson telescopes are available for use and members should contact him if they are interested in borrowing them.

Mike introduced Chris Jones who is giving his talk virtually via zoom called “Large telescopes – a blessing or just a pain in the observatory?”

Chris opened his talk talking about the huge variety of telescopes on offer and started with refractors, he then went on to discuss reflectors and finished with catadioptric giving the pros and cons of each.

He said that one on of the biggest issues in using a telescope is the focal length, fast telescopes have a focal ratio of 5 and below make friendly easy to use telescopes but they do have their problems.

Chris then went on to discuss different types of mount including Equatorial, Fork and Dobson mountings.

The effects of the atmosphere, collimation and age of the observer all have a bearing on the limiting magnitude of a telescope as does the size of the telescopes main optic. Chris presented a graph showing telescopes resolving power and light grasp compared with cost. He said that taking all things into consideration a 10inch reflector is probably the best compromise giving the best optical performance and ease of use for your money.

Housing the telescope could be a big problem if it is very big, Chris spoke about his experiences with a big telescope housed in a dome and how his head got trapped between the eyepiece and the dome, and how he wished the observatory was much bigger!

Chris is a variable star observer and he showed us the light curves of two novas V1678 Her and a very peculiar nova V1505 Cas, carefully explaining what was going on.

The data for the curves were gathered by him using his 18inch NGT Dobsonian telescope.

He then finished of the session by taking questions from the members.

What a very interesting Night we had.

[cpastro] This weeks club meeting Wednesday 13 October 2021

Hi All

This week we have Chris Jones giving a talk called

“Large telescopes – a blessing or just a pain in the observatory?”

For the first time we have a virtual speaker at the club.

Anything could happen.

Don't miss it!