If you can recognise these, you have passed the test as a good experienced amateur astronomer. As a further clue, I also got a decent picture of a galaxy nearby, just one field width off to the North. I believe 6 x 30 second pictures on the 20" telescope is all it took to get the raw pictures, but the processing was what removed the light pollution and brought all the detail out, especially on the left galaxy.Friday, 20 February 2009
A couple of nice spiral galaxies
If you can recognise these, you have passed the test as a good experienced amateur astronomer. As a further clue, I also got a decent picture of a galaxy nearby, just one field width off to the North. I believe 6 x 30 second pictures on the 20" telescope is all it took to get the raw pictures, but the processing was what removed the light pollution and brought all the detail out, especially on the left galaxy.The Night-Knight
Yes it's a rubbish pun but this looks exactly like the chesspiece. I took a plethora of exposures of assorted lengths through John G.'s filter and detrailed them all eventually. I have found an alternative way of doing this in Paint Shop Pro 7 using layers and 'darken' like the Photoshop method. The result looks quite good small. Pretty smooth. I played around with the pixel value mapping curves to process the stacked image. The vast red cloud IC 434 shines in hydrogen light so it's called an H II ('H-two') region. This light, unfortunately for our visual range of colour, is mostly 656.28 nanometres (H α) in the red, but a very tiny proportion is H β at 486.13 nm, which is in the blue region, enabling us to see it, barely! It's still too faint for my liking - the best I saw was a smudgy line with a gap in it where the horse's head is. This gap is a dark nebula, a dense protrusion called Barnard 33 (B 33) or The Horsehead Nebula that is part of an awesomely sized dust cloud floating in front of one side of IC 434. The blue cloud is a reflection nebula (NGC 2023).
Saturday, 31 January 2009
Leo I
Thursday, 29 January 2009
A stellar tantrum
One of our Society (John G - please visit his blog: see link) bought a 2" UHC filter that he lent me, so being knowledgeable of the sky, and it being winter, I decided to try it out on a rather strange patch of nebulosity near Sirius called 'Thor's Helmet'. After screwing the filter in place on my Camera adaptor and refocusing, I did a range of exposures from 30 seconds to 3 minutes, all of the longer ones trailing, and some of the 30 second ones trailing also. I detrailed all the trailed ones using the filter manually in Paint Shop Pro 7 just as jpegs, and ran them through Deep Sky Stacker. I was struck with the beauty of the resulting picture that appeared in front of me. And when I processed them in PSP7 I was stunned with the result. DSS selected 18 exposures, most 30 seconds, 3 of about 70" and 2 about 3', but equivalent to ~30" because of the detrailing process, of which it took an adaptive weighted average. Thor's Helmet, NGC 2359, is 7º from Sirius and exists because of a frantic massive star, called a Wolf-Rayet star near its centre. There is Oxygen O III (or O2+) emission in the centre and Hydrogen clouds further out.
Phoebe

I did hours of detective work recently, trying to find which little smudge on my processed images corresponded to Saturn's outer moon Phoebe. Both my sky chart programs were completely wrong with its position and I had to follow-up with some more images 3 days later. It's a rather lovely name for a very porous, dim, reddish rock that orbits in a 550 day retrograde orbit. She spins in 9 hours, so is not tidally locked like the other moons (and our own), leading astronomers to think it could be a captured asteroid. I'm amazed it was detected in 1898; it's only 16.45 magnitude! Take a look at the hi-res Cassini pictures to see how unbelievably full of holes it is. It was a case of taking 4 x 15 second exposures for each area around Saturn and stacking them to reduce noise. Here is the labelled version of the Tuesday night (Weds morning) when more moons were visible. The planet is rather overexposed (if you were wondering where the rings are).
Sunday, 11 January 2009
Sol
My attempt at stitching photos together.
This is a worthy subject for a panorama: M33 the close spiral galaxy. It has lots of nebulae and clumps of stars visible - click on it and scrutinise the outer regions. I did 4 x 4 x 15 second pictures on the 20" scope with the centre of the galaxy in each corner and tried to stitch them together using the camera's software. The brightnesses were all different - I spent ages trying to adjust the brightness of different parts of the final picture but I had to stop sometime. I don't know of any free software that can easily correct for these subtle brightness differences. Anyway, my previous M33 pic (below) made it into print in my society's newsletter... but I've done as I said in the accompanying post and taken an improved picture (without any of those trailed smudges or the heavy blue bias).
Interacting galaxies
Friday, 9 January 2009
Cosmic Keyhole
NGC 1535
Tiny planetary nebula
Sunday, 28 December 2008
Jones 1
...or to give it it's proper title, PK 104-29.1 . This planetary nebula was not picked up during the first great sky survey of about 10,000 deep sky objects for the New General Catalogue and the Index Catalogues. It is about 12.7 visual /15.1 photographic magnitude and its blue glow is spread over the two main arcs of a twisted ring over 5' in diameter. I saw the glow from one arc in the 20", but using a Lumicon UHC filter I could see both arcs and make out the ring - it was faint but easy after 10 minutes dark adaption - both of us present saw it visually this way. The central star is very blue and magnitude 15.7 easily captured in this image comprising of 9 x 30 second exposures (without detrailing). It is easily located (but not seen!) by going 1ºSSE of 72 Peg which is just north of the Square of Pegasus.
How many galaxies can you spot?
Sitting in the control room below the main dome, I was browsing the deep sky software and decided to slew the 20" toward the hitherto unknown (cliché) Pisces Cloud. I went upstairs and visually located NGC 403 and hopped over to the galaxies, which I could see as a few fuzzy patches strung out more or less in a straight line. I stuck the camera on and collected lots of trailed 30 second exposures. This is the current problem with the scope - not that it doesn't know where it is, but something somewhere is causing a quasi-periodic error. I later detrailed these and got 14 reasonable shots that I stacked and aggresively processed. You can see the purple amplifier glow at the bottom right and some headlight/light pollution residual artefact across the picture (taking flat-field images addresses this issue but make the problem worse before they make it better in these circumstances). I think it looks cosmic.
Venus, Jupiter and a Plane
Here's one of the scenic examples of my shots. It is of the observatory building showing the dome glinting in the moonlight and also features a plane flying in the distance behind it and the planets Venus and Jupiter. This wide-field photograph of 15 seconds at f/5.6 was taken on December 6th shortly after sunset at 1730 UT and has also captured some annoying but in this case quite aesthetically pleasing light pollution.
Looking back to the summer sky in an icy winter wind
This picture of M57 was taken from the observatory dome with an icy wind blowing in the opening, soon after dusk twlilight with Lyra and Cygnus still reasonably high in the western sky. The only problems being 1. car headlights and 2. a buffeted telescope. I couldn't get any 30-second shots without trails, so I de-trailed them all (phew!) and stacked the best 16 of them. Despite the de-trailing artefacts which appear as streaky noise you can easily make out IC 1296 the 15.1 magnitude spiral galaxy to the right.
Using my f/10 SCT at f/4
As I do astronomy on a budget, I like to see what I can fudge together or get away with. I do not have sophisticated tracking equipment on my SCT, just the R.A. motor and a manual guiding 1 x sidereal rate hand controller. This would suffice if I were to enjoy spending hours typically at -2ºC, hunched over an eyepiece, trying to counter the effects of wind and drift in my motor versus the sidereal rotation of the earth. I can't be doing with this and my knowledge of optics tells me that at f/4 compared with f/10 optics, the light gathered per area is 2.5x2.5=6.25 times greater thus shortening exposure times. I got hold of a second f/6.3 field flattener and after many long attempts with various coupling adapters I found a combination that worked with the focus at the end of its travel. I had to use a 1 1/4" adapter (I will get hold of a 2" version ASAP) so the vignetting (edge-of-field clipping) is quite severe; still it gives it a lovely 'through the telescope' quality! This is the Pleiades with an effective focal length of 800mm and aperture of 200mm in a single shot of about a minute.
Wednesday, 3 December 2008
A fire in space
Mae'n dda gen i gyda hyn Lluniau y Niwl Ffagl. Mwynhau.
Ich bin mit dieser Abbildung des Flamme-Nebelflecks sehr erfreut. Genießen Sie.
Είμαι πολύ ευτυχής με αυτήν την εικόνα του νεφελώματος φλογών. Απολαύστε.
Je suis très heureux avec cette image de la nébuleuse de flamme. Appréciez.
Sunday, 30 November 2008
M1
Monday, 24 November 2008
Orion is back. Hail winter!
Saturday, 1 November 2008
A Hallowe'en night moon.
The observatory scope has just been recollimated, which enabled me to visually spot Titania, a magnitude 14½ moon, 20 arc-seconds below the 6th magnitude planet Uranus, which appeared at 200x as a very clear bright green disk, wobbling around in the atmosphere. I thought I'd have another go at some pictures of the moons, and there were some surprising background stars right behind the planet. I saw 2 moons, stacked 6 5 second pictures and revealed a 3rd. So here are Titania, Umbriel and Oberon. We quite like the effect of the starburst cross on the planet, which is 3000 times brighter than the moons. Incidentally, we had a little bother identifying the moons using astronomy software, as it didn't allow for the almost 3 hour light time and they move significantly in this time!
Thursday, 30 October 2008
Cosmic Catherine Wheel
I went galaxy hunting the other night. This is a closer up version of the pinwheel galaxy or M33, shown below when I tested my 400mm camera lens. I got 6 30 second pictures on the 20" scope, all were very trailed in different ways, but I detrailed them all seperately, painstakingly! Then I stacked them, hoping that the trail artefacts left over would somehow "average out". Anyway there was a lot of red background noise, so I had to make the colour a bit bluish for the galaxy to stand out - as its light is very spread out. Good result I think?
A distant galaxy cluster

This is the faintest thing I've tried to take a pic of so far. It's 4 exposures combined from 15 seconds to 1 minute on the f/4.8 20" scope, at ISO 1600 (fastest film setting) on my Canon Camera. It looked good considering it's a collection of 14th magnitude galaxies. It is in Pegasus, near NGC 7331 and is called Stefan's Quintet. I've even picked up one galaxy on the image that's not in the PGC/UG catalogue on the far lower left! Impressive for such a short exposure, but not good for traces of trails left from my de-trailing
Monday, 13 October 2008
An autumn gem
NGC 246: I have always had trouble seeing this object as its light is spread over a large area, but I got a good view at low power through a nebular filter. It lies right in the middle of a triangle of stars including Diphda in western Cetus and its central star is double (3.8"). It is a close planetary nebula, well, close in planetary nebula terms at 2100 light years (Hipparcos). Sometimes called the Skull nebula, it is in Patrick Moore's Caldwell Catalogue at number 56 and was discovered by William Herschel in 1785.
Shakespeare's characters reveal themselves
Logically, following the image of Neptune's big moon, Triton I wanted to see other faint moons. Conversely, the moons around the much closer and 7 times brighter planet Uranus are fainter. However the brighter ones number 4 or 5 and rather poetically they are all named after characters from Shakespeare plays. In this picture, comprising of thirteen 3.2 second exposures, I just managed to get three. Fifteenth magnitude Umbriel is hiding just south of the planet's glare; below it are Oberon and Titania at 14.2 and 14.0 magnitude respectively. Also, rather confusingly is a faint star. This is a preliminary picture, which I hope to improve on as it is somewhat trailed and inexactly focused.
Sunday, 12 October 2008
How far south can you comfortably go?
I wanted to get a nice pic of NGC253 - the Sculptor galaxy and surprise folk by the fact it was in Sculptor, a constellation that is barely visible from UK. But to my astonishment, one of our club's members had just got a beautiful shot of it taken via the web on a Ritchey-Chrétien 10" in Australia. Nevertheless, I got a shot of it the following night on the 20". It's had a lot of light pollution subtracted off and I can't say my flat field was good enough to correct for the vignetting effect at the edges.
20" Mirror Test - part 2 small targets
One of my challenges since seeing Triton around Neptune in a 10" scope, was to image it. I didn't realise how easy this would be. It only took a few 4 - 10 second exposures on the 20" scope to easily capture Triton, which is 13.5 magnitude, and pinkish compared to Neptune's bluish. The separation is about 15 arc seconds, so there is either a tiny bit of coma or more likely inexact focusing.
20" Mirror Test - part 1 deep sky
Monday, 29 September 2008
Our overlooked galactic neighbour
Uranus
Monday, 25 August 2008
New lens test.

Saturday, 23 August 2008
A fantastic composition... a culmination of many natural sights!

Moon with Earthshine, Dawn twlilight, Noctilucent Clouds (very high ice clouds caused by meteoric dust), and the Pleiades cluster (M 45). 3 second exposure 75mm (x35/25) zoom lens, manual focus, rested on the roof of a car (with the engine switched on), without a cable release.
The other edge of the Veil
A swan and a lagoon on a midsummer's night


Friday, 22 August 2008
Pluto...not a planet, just a dot.
The Great Orion Nebula, M 42
Wednesday, 6 August 2008
Tough shot
Star de-trailing

Some planets...





