Crater Clavius and surrounds

In celebration for being on this planet for threescore years and ten, I upgraded my astrophotography armoury, firstly with an equatorial “goto” mount (Skywatcher Star Adventurer GTi), and secondly with a new camera, the ZWO ASI715MC. The equatorial mount solves the problem of field rotation in long exposures, and also the occasional glitches in tracking that I have with the alt-az telescope mount (which will have a continuing use both for astronomy and for amateur radio). This first image taken with a reasonably good sky (I have waited for ages; I took some images a few days earler, but they were through cloud and not as good!) is of the area of the Moon’s south polar regions centred on the crater Clavius.

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Orion nebula M42

I return to the Orion Nebula, M42, because it is one of my favourite subjects. When I first used my new telescope (100mm aperture f/5 Skywaycher Startravel 102) and pointed it at the Orion Nebula, I was so surprised to be able to see so much of the nebula by eye in the dark skies of Dumfries and Galloway. Then when I took some photos with the Nikon DSLR, I was simply amazed by what appeared on the screen with only a 20 second exposure. This is another attempt; it’s a stack of 33 ten second exposures, a total of 5m 30s, with a flat field correction applied. The focus was set up properly using a Bahtinov mask on the bright star Rigel, and I think this shows in the improvement in quality from the previous image.

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.

The Milky Way

Having dark skies in Dumfries and Galloway is great. It means that on a moonless night the Milky Way is visible, and the autumn views are best because there’s a nice bright bit almost overhead. Here’s the Milky Way in the region of the “summer triangle” of stars Vega, Deneb and Altair; I have added annotations for some constellations. This is just taken with my ordinary Nikon D3100 DSLR, and is a stack of 10 second exposures at f/1.8 with my 35mm lens, to give a total exposure of 2m 20s. The reason for the short exposures is that I was not usuing a tracking mount; the camera was simply held fixed.

There has been a lot of hype in the media about this comet, but it was never going to be really bright. I started to think about trying a photo as it approached its brightest, but the weather made this difficult. However I finally got the chance to try properly when the skies cleared yesterday.

This is a heavily processed image, made by adding 26 exposures each of 10 seconds, taken using my 500mm focal length f/4 (approximately) Skywatcher Startravel 102T telescope with a Nikon D3100 DSLR on an alt-az tracking mount. The camera was set to ISO 3200. The image stacking was done with DeepSkyStacker, followed by a little image processing there, then rather more adjustment using Gimp.
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Orion nebula image

In March last year I obtained a photo of the Orion nebula that I was quite pleased with, but later was a little frustrated that my old 3 inch (75mm) aperture refracting telescope was a bit wobbly on my new alt-az driven mount, as it’s so long. I have been trying an assortment of long photographic lenses, but this year took the plunge and got a compact 500mm focal length telescope with a 100mm objective lens.

I have finally been able to try it out in dark skies, and was first of all really pleased by the view of M42 through the eyepiece. A few days later I was able to get the camera on the end of the telescope, and the very first image on the back of the camera had me amazed. It was just a 20 second exposure, but showed so much.

The image above is a stacked composite of 8 images, total 160 seconds exposure, ISO 1600, using RAW format. I fiddled a bit with the contrast etc to get the result here, but I can see that I will have a lot of fun with this setup.