M31 galaxy

For a while I have wanted to take an image of M31 using the new(ish) telescope. It’s a great target, and has always impressed me because I know its real size on the sky – it’s really about 3 degrees – or six full Moons – across! We can just about see the tiny brightest part of the nucleus with the naked eye in a dark sky; with binoculars it’s a bit bigger, and in a photograph you start to see its true size. To me it was most spectacular on a thin glass plate image taken with the Schmidt telescope at the Palomar observatory, when I was using photographs like that as a professional astronomer.

This is very much a first try. It is a stack from just three 30 second exposures at prime focus of my 500mm f/5 telescope, ISO 1600. It’s cropped to square, and has a bit of colour curve processing to increase the colour saturation. I had real difficulty getting the alt-az mount aligned (not helped by bright lights at eye level around the field where I was working) and from a sequence of nearly 50 images only a few were untrailed (even though quite a few had very small trails). Next time I will do better!

Standing stone

It’s 50 years since a group of undergraduates from the Cambridge University Astronomical Society had a holiday surveying megalithic sites in Argyll to investigate possible astronomical alignments. It was a lot of fun, and we even wrote it up and the results were published in a paper in Nature 253, 431‑433 (1975) which was probably something of an achievement at the time, though I’m not sure that we realised how much!

We had a great time meeting up and revisiting old haunts in the area.

Trinity College Great Court

I recently attended the Annual Gathering at my college for those who matriculated in 1972 and 1973. It was very enjoyable, and great to be back with old friends in very familiar surroundings after such a long time.

After a period of rather sporadic posts on here, I am finally (I think) in a fit state of mind to post a bit more stuff, and catch up with some of the things that might have been posted at the time. The last few years have been hard for many people, and though physically I have been fine, the effect of lockdowns and the abysmal behaviour of many governments in particular depressed me greatly. Let’s hope that people are never daft enough to let it happen again.

Clock mechanism

After a long pause I have returned to testing the clock mechanism. I have made some repairs to the components that make the chime work at the right time and for the right number of bings of the bell. One lever had been repaired a long time ago, but the repair had failed. A spring was also rather bent and not acting well enough.

I suspect that the original repairs may have been made by my great grandfather who once owned the clock!

Initial tests show that it chimes correctly, but it needs to be run through quite a few cycles to have some confidence that the repair has worked.