Wednesday, 17 November 2010

California here we come

This is a little bit of the California nebula (NGC 1499) taken with the autoguided 20" scope. I combined 6 x 90 second exposures. It makes sense in theory to get as long exposures as possible, because it's not just a case of taking more shorter exposures. With the longer exposures, there is less noise, because a large part of the noise is from reading the sensor. The problem we have is rotation, which limits the exposure time until you see stars forming short trailed arcs at a distance from the guide star. Therefore, we can only do long exposures in the East or West. Had my camera been modified for astronomy, this picture would be full of bright red nebula.
As it is, it is pink, but still lovely.

NGC 1501

Little close up of the best few 30 second subexposures of this quirky green ring living up in the faint northern constellation, Camelopardalis. The camel-leopard is a giraffe, of course. I processed it with patience in Registax, which is great at sharpening, but doesn't seem to be able to rotate and stack, nor stack dark frames. So I cropped it.

Galaxy hiding behind star

This is Mirach, in Andromeda, blazing away as a bright, 2nd magnitude star, 200 light years away from us. In the same line of sight, absolutely unconnected, lies NGC 404, a faint 10th magnitude galaxy that is rather hidden in the glare of Mirach. The galaxy is many millions of light years away, but the smudge we see is only 1500th as bright as the star, and that light is spread out so as to make it yet harder to see. This picture is exposed and processed so the difference is nowhere near that great. Good things, digital images!

NGC 6905

Here’s a little planetary nebula in Delphinus. Another one of my ‘unusual’ objects, not in the sense that it’s difficult to photograph, but not many people would think of photographing it. It was visible as a little ring in the 20” and I could just see the central star. Wow! There are two brighter arcs to the west and east (top left and bottom right in this orientation) and there are faint extensions (ansae) to the north and south, that show up better on longer exposure photos.

The Fireworks galaxy (NGC 6946 in Cepheus)

In this little Catherine wheel of a galaxy there have been lots of supernovae, hence the title. It makes us wonder why there aren’t as many in our own Galaxy, the Milky Way. But we realise we are IN our galaxy, and it is full of DUST. I use the word full loosely. The dust blocks our view of the majority of our galaxy, and so we’re unlikely to have seen all the supernovae that have gone off in the last few hundred years. So come on, Betelgeuse or rho Cassiopeiae, give us a nice show soon.

Stefan’s Quintet (Pegasus)

This little galaxy group is a challenge to see in most amateur telescopes. However, I have seen all 5 galaxies in our 20” scope. It’s rather trailed as it was taken before the auto-guiding camera was used on the big scope. Also it was high in the sky so the scope had to spin rather quickly to keep track of it. Consequently, there is some rotation, which appears to pivot around the star at the top. This is a sign that the computer did not quite know exactly what position the telescope was in. Looking at this group makes me wonder how our own local group would look from a planet there. It would be a patch of dim smudges in a large telescope, dominated by Andromeda, the Milky Way and M33, rather further apart.

Hartley 2

Here is a picture of the Comet Hartley 2 from 10th October (not very current). Perhaps it should be renamed Harley 2, because of its ability to move during the time it takes for its picture to be taken. The green colour comes mostly from the molecule C2. Hmm... I wonder what that smells like. I tried to process to give the most coma and tail, but probably have included some optical artefacts due to not using a flat field correction to the image.

Wednesday, 3 November 2010

I (also) see 405... and it is VERY interesting.

Disclaimer: apologies 'littlebeck'... I couldn't resist posting this first. I'm in a rare mood for blogging, and I thought this picture couldn't wait any longer for its submission into the blogosphere. For the reader, we were both attendant at the ultimate test of the 20"'s guiding using an STV camera - a 5 minute exposure on an alt-az scope, and this pic didn't actually come from my Canon EOS 350D. I was impatiently waiting to test my own camera and its focal-reducing adapter before imminent cloud arrival (see IC410 post). Here is my stack of the 5 good 5 minute shots of IC405. This is such a wierd looking patch of sky, and in this instance the Canon's lack of red sensitivity has enhanced the colour contrast between the different parts of the nebula. The nebula is otherwise known as the Flaming Star Nebula, and this is just the centre surrounding the 6th magnitude star in the shot (the faintest star you can see, unaided). This star was the guide star and was responsible for the STV units loud beeps as it corrected the telescope's position. (P.S. I'm currently listening to Radiohead: Everything In Its Right Place and reading too much meaning into song lyrics).

Sunday, 31 October 2010

I see 410

IC410 is the little patch of nebula in Auriga that I used to test the autoguiding mechanism of our big scope. I used 1 minute exposures; we previously had success with 5 minute exposures, but I was playing safe. The flat field pictures I took afterwards using a diffuser and skyglow seem to have added a lot of noise to the picture and it still required more tinkering with the background, hence the patchiness. I'll have to play around with using false or smoothed flats. This picture used 17 x 1 minute exposures at ~ f/3 on the 20", darks & flats. The Sky Quality was only 20.66 mag/sq" (a bit disappointingly light), which didn't help. This was taken after the successful (see 'littlebeck') 5 x 5 min picture of the centre of IC 405.

Wednesday, 27 October 2010

A winter spectacle seen on an autumn predawn

ON this wide picture of the Great Orion Nebula complex, you’ll see the beautiful clouds of gas and dust reflecting and fluorescing the light from the bright blue stars at the centre. If you step back and take in the grand scene, all 10 square degrees of it, you will start to see among the bright blue stars, a few little orange stars. And then, towards the lower right, a few of the background Milky Way stars start to creep into shot. Fingers of opaque, black dust can just be made out streaming off to the right, by virtue of the incursions of stars visible behind it. All of which gives you a clue to the real size of this patch of interstellar material. I find it very odd how a vertical line of four different types of object have arranged themselves on the sky like this, for us to see (check out Messier 8). Not bad for a 2 minute exposure (18/09/10).

Conjunction of jollity and magic

According to Gustav Holst, Jupiter is the bringer of jollity, and Uranus, the magician. Here we can see the two planets on the same photo, and not just that, but with moons. Jupiter is overexposed and overprocessed, so much so, that you can see its reflection in the lens. There is only 1 degree between the planets at this time. Uranus compares well in brightness with Jupiter’s moons. I couldn’t see the planet with my naked eye as it’s still too light polluted and/or misty here. Despite being easier to find, Jupiter’s glare contrarily makes Uranus more difficult to see.

Mercury Rising

It was the coldest night for ages, about 3 or 4 ºC, but finally at about quarter to six I saw Mercury emerging from the cloud tops near its eastern elongation from the sun. This is a stack of 4 pics that were slightly out of focus, but the composition looked better. Mercury was in Leo, hovering below the lion's front paw.

Thursday, 7 October 2010

Ganymede's little shadow

Sorry for the delay, but no mirror = no posts (also no clear skies). My own "little" Schmidt-Cassegrain Telescope has had motor drive problems so not many pics from that either. However, I did manage to see Mercury and Uranus with it on 18th Sep at dawn from behind the sand dunes on the east coast. The picture I chose to post was taken that morning, when Ganymede started to cast a little shadow on the edge of Jupiter at about 4:20. The Canon was inserted directly into a 2x barlow lens on my 8" Meade SCT, creating an effective 4m focal length at f/20. A few raw-format subexposures at ISO 100 were stacked.

Monday, 6 September 2010

Green eye

I bet there are not many people out there that recognise this object. To me, it looks like an evil green eye. Not quite as evil as the terrifying Mayall-Cannon 18! (Here I refer to Paul Money's favourite pics lecture part 2). I suppose it's possible to plate-solve the stars and if you did this you would find this object lies somewhere to the left of Cygnus. It is Abell 78 and there is a hint of an outer part below it. I decided to stick to RAW format for this one, where I sacrificed time and memory for less noise. It is a faint little nebula, only about 14th magnitude and spread over just under 2 arc minutes.

Sunday, 5 September 2010

Little ring galaxy

This is the last image made with the big telescope before the mirror was taken for an emergency realuminisation. It's a wierd 'little' galaxy 72 million l.y. away in Pegasus, with a bright yellow nucleus and a detached blue ring surrounding it. There is a larger halo, that doesn't really show up in this image, comprising of 31 only 12 second images at f/3. I was having issues with the tracking so I had to keep the pics short, but on closer inspection, each image still had slight star trails or a touch azimuthal shake or wobble. You can see the colour of the nucleus compared with the star nearby. It's about a 7' x 9' field centred on NGC 7742.

Monday, 23 August 2010

Tempel 2

Here's a pic of a comet that's floating around in Cetus at the moment. On the spur of the moment I used my mobile to visit the heavens above website for charts and pointed the big scope at it. It was difficult to get a decent photo, mainly because it was quite low down in a poor quality sky. Compared with the usual capacity of the 'big' scope to gather light from 17th magnitude galaxies for your camera, you wouldn't imagine 10P/Tempel 2 to be as bright as 8½ magnitude (~2800x brighter). I've always found comets much harder to see than their magnitude suggests. Maybe it's their diffuse nature that makes them so elusive.

Distant galaxy cluster

This cluster is a vast factor of ~ 3,000,000,000,000,000,000 times more distant than the meteors in the pictures below. It was taken on the newly driven 20" telescope in my usual way. It is centred on NGC 7242, a 12th magnitude galaxy, 2½ arc minutes across, the rest being about 15 or 16th magnitude and there is even an unlabelled 17th magnitude fuzzy spot (beneath the '72' of the label 7240), PGC 68416. There are a few other galaxies around this area, which is a small way South of the star 1 Lacertae, and I thought I'd get a quick pic while it was passing overhead.

Wednesday, 18 August 2010

Perseid 11:55pm Wed 11th Aug

Taken with a fish-eye lens on a Canon 350D from Salthouse Heath (1 minute exposure).

Perseid 11:50pm - quite faint

Look at the top - right in the centre of the Milky Way.

Perseid 11:18 pm Wed 11th Aug - v faint!

The North Sea is at the bottom. Is there some greenish aurora glow or is it just me?

Monday, 16 August 2010

Our Galaxy (even more of it!)

I carted the 8" SCT to "my" dark heath site again in search of some Perseids. Well... it's not so dark any more. How about that! As an aside I thought I would be obtaining another load of 1' pics through the fish-eye. The distortion has added every abberation under the sun but I still love the resulting image. Enjoy this super-wide picture of our Galaxy and all the constellations of the summer sky.

Monday, 12 July 2010

Looking across our Galaxy

Carl Sagan taught me that our Galaxy is always spelled with a capital G. Here it is. I used a slightly different technique with my Canon to get this image. I have an old 135mm f/2.8 lens with a thin M42 to Canon adapter. I thought this lens was no good, but aha! I was assuming that setting the lens to infinite focus gave infinite focus, mainly because it looks to all intents like it is throught the viewfinder. However, a slight tweak to the focus ring and it gives sharper focus. Still not perfect, but at least it does focus; it could have been out the other way and never reach infinity. Anyway... I'll stop that laborious explanation and say how I enjoyed polar scope aligning and then polar aligning an Autostar mount. I then piggybacked the camera on a scope and pointed it out of the dome to the beautiful summer milky way. I worked at ISO 800 so I could get longer exposures (6 x 1' plus a 2'). I think the trick was to get flats 'in situ' as well as darks and flat darks. These were obtained by scrunching a bit of bubble wrap in front of the lens and repeating 5 blurry shots close to the same area, covering the camera for 5 seconds when cars came past. I had to stack using 'Kappa-Sigma clipping' as opposed to 'Mean' even though one of the pics was 2 min and would effectively get ignored. Is that right? ... OK. Now let's play spot the objects!

Monday, 28 June 2010

Comet McNaught

Here's comet 2009 R1 McNaught looking rather lovely in the 20" in the early morning of June the 14th. I made it about 5.9 magnitude but that's with a lot of dawn twilight. I also snapped it with at least a degree long tail on the 22nd before midnight, and the 3 of us that observed it thought it looked greeny blue in the 8". This image, next to a bright star in Perseus, is probably the last image the 20" gave while using its old stepper motors with Scope software . It now has servo motors, digital encoders and new software/hardware in place (thanks to B.A.S.) and I can't wait to test it.

Saturday, 5 June 2010

Outcast shockwave

In the deep blue summer midnight sky, we were panning around the Veil Nebula using the 20-inch, which is a superb telescope for this sort of visual application. Using my wide field 20 mm eyepiece and a Lumicon UHC (Ultra High Contrast) nebular filter, the strands of nebulosity from this supernova remnant were standing out from the twilight background. After looking at the weird ethereal strands around 52 Cygni, we moved across to NGC 6992 and 6995 on the opposite side and followed this arc as far as possible. I came across what I thought was a faint blob well separated from the rest and was curious to confirm whether this was real or just my imagination. So I stuck the Canon onto the scope. I keep the focuser locked in position for the Camera and slide the eyepiece in and out for visual focus, so this was very quick. I got a few 30” pics and stacked to reveal this lonely, outcast piece of supernova remnant.

The Sting of the Scorpion.

We’ve been blessed with clear weather recently. So I thought I would test the transparency of the atmosphere by trying to see how far south I can see. As it is June, the constellation of Scorpius rises after dark, with its many stars of low declinations. The South horizon of the observatory is pretty good despite the healthy hedge growth this year. From latitude 52º 32’ 17” I thought I wouldn’t have much of a chance of seeing the stars ε and λ Scorpii at declinations -37 6’ & -37 18’. The stars, called Shaula and Lesath, represent the sting of the scorpion. But I caught my first glimpse of Shaula from Norfolk in binoculars. I took 65 x 5" shots with a 135mm f/2.8 lens on the 350D in two bursts during moonrise. The stacking process has given the picture a strange looking blurry horizon. Perhaps an animation is in order. The clusters M7 and M6 (top) along with 'the hockey stick' on the right make a nice composition.

Thursday, 27 May 2010

Comet 2009 R1 McNaught

..just a quick one to show what we have in the skies now. Here's last Saturday night's showing of the comet that's set to brighten and pop its head over the dawn horizon during June 2010. As the comet was low in the sky it is not a very deep image. It was quite unusual to be looking at the constellation Andromeda in May.

Wednesday, 26 May 2010

Monday, 24 May 2010

The black serpent from space

Here is the Snake nebula in Ophiuchus (Barnard 72). I snapped it Saturday night (may 22-3) at about 1 am. It is awesome to see what look from a distance like vast clouds of stars that stop abruptly at some mysterious black boundary. And what's more it's in the shape of a snake! And here the snake is slithering across the heavens towards another even blacker shape. For this picture it was useful to have my remote shutter control timer, so I could go off and drink tea while about 30 x 15" shots were being taken on the 20" scope at f/3. Thanks Keith!

Friday, 16 April 2010


We have a good range of planets up at the moment. I trained the recently collimated 235mm Celestron on all of them. I used a -5D Barlow I found lying around and took a few snaps of each planet on my Canon EOS 350D through it, giving a focal length of about 4.5m at f/20. Exposure bracketing was done and I stacked the best few images of each planet. After contrast enhancements and aligning the red, green and blue channels etc., I put all 4 together to compare size for size & colour for colour. I worked my way round the sky from twilight to opposition, i.e. in order of increasing Right Ascension hour. Then I checked out the view of Saturn. Very sharp! I saw a very interesting alignment of moons next to the rings (Monday 12th April), so checked it out on the 20". This was brighter, but fuzzier. I attempted to image the moons but the tracking / vibration wasn't good enough on either scope. Shame - there were four moons above 12th magnitude within about 3 arc seconds.

Saturday, 3 April 2010

The Whirlpool

This fine galaxy is filled with fascinating features. The Whirlpool galaxy (M 51) is now climbing high in the sky and can be found near the tail star of the Plough, Alkaid. It is not one but two galaxies, the second (NGC 5195) has been shown by computer simulation to have passed through the main one twice. I am pleased to have revealed in this image the glowing areas of stars surrounding NGC 5195 that are the result of the aforementioned collision. To get this image I have combined the 10 least trailed shots with 19 very badly tracked ones, which I detrailed using Paint Shop's Layer/Darken function. I stacked the first 10, then all 29, and processed them both separately, applying a careful smoothing blur to the faint areas. Only by stacking all 29 shots could I clearly see the filament shooting out at the top of the image. I then cropped both to the same area and blended them in the ratio about 2:1 in favour of the sharper 10 frames. The total exposure time was just 15 minutes at f/3. I was quite taken aback when my stacking program output showed me the extremely deep areas to the left, which have incredibly subtle contrast against the sky background.
Another great thing in this picture is the exceedingly thin splinter of IC 4277, a 16.5 magnitude galaxy hiding just to the left of the main galaxies. This has one of the highest aspect ratios I've seen although it has been a little blurred in the processing. IC 4278 is also here, lying below NGC 5195.
Imaging reveals so much more than the eye will ever see directly. Even the Sixth Earl of Rosse would never have seen anything like this when he made his famous drawing of this object on his 72-inch Leviathan telescope at Birr Castle.

Thursday, 1 April 2010

Equinox Sunset

Here, at 6 p.m. old local time on March 21st, our Sun is being refracted up over the horizon at the midpoint of its biannual, azimuthal journey (also known as due West). This astronomical occurrence is called the vernal equinox and has the historical significance of marking the transition to the growing season in the northern hemisphere. In this picture, as well as industry creeping into this once pure event, an aircraft contrail has formed a cirrus cloud that obscures part of the Sun. Both signs of humans' influence on nature. [Canon EOS 350D Ljpg ISO 100 1/4000" 400mm lens @ f/15].

The Glorious Orion Nebula

This was an exercise in using a telescope that doesn't give sharp resolution stars, to generate an extra-sharp picture. The idea came to me at the telescope, while peering at the Orion Nebula. The secret is that it is a mosaic of 15 pictures. Each was a 15-second exposure taken at f/4.8 on the 20" scope during a full moon last year, all except for the central nebula, which was 4 seconds. The Canon Photo Stitch software has never given me an acceptable result, so I spent a few days correcting numerous patches of the background until I decided I'd just make it all an even black. Hence it is not an accurate representation of the sky - no photo ever is. It's still a little grainy in some areas and not a very deep image, but it's so much more aesthetically pleasing to have sharp stars!

Thursday, 25 March 2010

Siamese Twins

The Siamese Twins are a pair of overlapping and presumably interacting galaxies aka NGC 4567 & 8. Their magnitudes are approx. 11.7 and 12.1 and they are quite small, 4.6 & 3.1 arcminutes (respectively), because of their large distance of 120 million light years from Earth.
The pulses sent to the stepper motors that drive our 20" scope had just been adjusted to attempt to cut the wobbly, vibrating tracking, so I gave it a test on these fine objects. I did manage to get one reasonably steady 2-minute exposure, but on closer inspection there were slight star trails, in addition to the field rotation limiting the exposure. But overall it was no better, I'm afraid. I had to detrail most of the 30-second images that made up this final image, but a pleasing result nevertheless with a total exposure of 5 minutes at f/3 ish, with quite a misty sky just before moonset. Also in this image at top is NGC 4565 - a 12.0m, 3.2' galaxy and at bottom, IC 3578 - a 15.1m, 0.9', tiny splash of light.

Saturday, 20 March 2010

Gyulbudaghian's brightening

Here is an image showing the brightening of Gyulbudaghian's variable nebula, located at RA 20h 45' 55" and Declination +67º 57' 45" in Cepheus. There is clearly more of the cometary looking nebulosity north of the star PV Cephei. The image is a stack of 57 30-second exposures at ISO 1600 and f/3 on the 20" scope, taken on 8th March 2010. But the processing used non-linear stretches and an artificially created and edited flat field to give the most pleasing picture, so in no way is it quantitatively calibrated. It looks wonderful in such a large format and it's nice to have sort of discovered something changing up there in the stillness of space!

Sunday, 14 March 2010

The Air Pump

I am now going below the -30º Declination line to reveal a couple of galaxies in the constellation of Antlia, the Air Pump. Imaged from the UK, NGC 3100 and 3095 are both below 12th magnitude in brightness and -31º30' in declination. As you can see, with the low altitude, the atmosphere has shaken the stars into big disks, after realigning the Red, Green and Blue channels as a matter of course. I also spent ages messing around with the background subtraction, as the raw images were a bright milky brown. 27 x 15" f/3, f~1.5m, ISO 1600.

Galaxies in Pyxis

On my southern trawl, culminating a little after Puppis the Poop, comes the constellation Pyxis the Compass. It contained the fine galaxy NGC 2613 (11.2m) and faintly above it PGC 23977 (14.5m). Thanks to the huge aperture and excellent south horizon the telescope could cut through the large thickness of misty atmosphere.

NGC 2452 & 2453, Puppis

I turned the scope to the southerly declinations of Puppis for these interesting and glorious full-colour shots of the cluster and planetary nebula NGC 2452 & 3, respectively. Being near the milky way there are some beautiful star patterns, and a deep orange star on the right. The cluster looks like a backwards lambda to me and the planetary is a tiny or distant little pair of blue lobes.

Friday, 12 March 2010


Here's an animation of Makemake, from last Saturday and Sunday nights (March 7, 02:00 & 23:00UT) on the 20" scope. It appears surprisingly bright for an 16.8 magnitude object. Conditions were dark and transparent both nights and I was at quite a high altitude. This little heavenly body was surprisingly easy to find after having imaged Eris (see earlier post) as it lies close to the top dot-to-dot line of Coma Berenices. Makemake, which I believe is pronounced mak-eh-mak-eh, is a large minor planet over 50 A.U. from the sun, which puts it beyond Pluto's orbit, but nowhere near as far out as Eris. I acquired 29 x 30" images the first night, then another 11 the following night, when it was darker and clearer still. -- Hit play to reload the video as it's not set to repeat...and apologies for not adjusting the brightness.

Tuesday, 23 February 2010

Weird Wild

Here's Comet Wild from 01:30 20/2/10 looking particularly weird. There are two tails, one of which is curved in a strange way from this line of sight. The sub-frames looked like the coma was smeared out left-right. I fiddled a bit with the processing to reveal more of the faint tail at the expense of the coloured background, which is probably the result of a light pollution gradient, or an out of date flat field. It is 9 x 30" pics on the 20". Wild is visible in the morning sky in the constellation Virgo.

Comet Schwassmann-Wachmann 1

Here's a current shot of Comet Schwassmann-Wachmann 1, which has been in 'outburst' recently. It looks a bit like Holmes did, as it has an expanding shell. The image was taken at about midnight on 20/2/10, is linear and results from 19 x 15" + 1 x 30" stacked light frames at f/3 ish on the 20". It is currently about 11th magnitude in W Leo.

Saturday, 20 February 2010

IC 342

For those of you that are checking this blog to see how well the 20" telescope performed after it's mini-service, then the answer is ... pretty well. It may be a little louder and a play a slightly different tune while it's working but it is much smoother and hasn't been this easy to image on for a long while. We had what most telescope users expect, stars that keep pretty still for 10 30 second frames. There was some trailing, but not much, and not all that dancing about that I've been used to recently. So thanks - we got a lot of interesting pics taken last night. Here's one of them - a far out IC object called IC 342. It is a faint face-on galaxy in Camelopardalis and it is seen dimmed through the milky way's dust. So it may be close and 21 arc minutes across, but is only 9.2 magnitude. Only the middle spot showed up on the 30-second sub frames. So it was a bit of a swine to find; we successfully used a 14.2 magnitude galaxy as a GOTO/reference object!!

Monday, 15 February 2010

IC 289

Here I am pointing out an overlooked object. It's not in the Herschel 400, the Caldwell catalog, nor the original New General Catalogue. It lies less than 3º from the easily visible (4.2m) star CS Camelopardalis, which is itself a ridiculously overlooked (double) star in the 'unfashionable' constellation of the giraffe. CS Cam doesn't have a Bayer letter designation, or even a Flamsteed number and lies an unmeasurable distance away. Still, IC 289 is a lovely little(!) 12th magnitude planetary nebula - the same magnitude technically as the Owl nebula in Ursa Major, which I find a bit hard to reconcile. The nebula itself is actually over the border in Cassiopeia. There are some lovely coloured stars in the field. There is a weird pattern over to the left, which is the Southern side, centred on a 9th magnitude brightish star. Moving slightly toward the corner, there appears to be a streak or 'hair' next to the 14th magnitude star. This is actually a little row of 5 stars, all in a neat line, that are just unresolved. Just below the 9th magnitude star is a faint reddish galaxy, looking a little smudgy. I find this image an exciting little exploration of space! Details: 20" @ f/3, ISO1600, 2½' on Canon EOS 350D, linear.

Sunday, 7 February 2010

Comet Siding Spring

On another frustrating night trying to control a confused telescope with a very rigid operating system I still somehow managed a few shots of Comet Siding Spring. We got a visual sighting of the comet before imaging. I had to star-hop to it through northern Boötes. It was not obvious at first that it was in the field of view and I may well have gone past it a couple of times. But this process was made much easier with the charts from The view was later improved greatly by putting in the zoom eyepiece. I find it very interesting that undermagnification causes the perception of less contrast, and even contrarily makes objects invisible while more light is reaching the back of your eye. The tracking was a serious problem, we corrected it for a few minutes using drift correction, but later on the scope ended up thinking it was about 25 degrees from where it was and nearly knocked over the step ladder. The frames were 6x15 and 2x30 seconds at f/3 ish on the 20" and I still had to be detrail by 2 or 3 pixels after stacking. Not bad for a low altitude comet dimmer than 10th mag and a slightly misty night.

14 Tauri occultation

Update from below...
I drove out to the observatory at midnight on a working weekday night, set up my tripod outside and pointed at the star 14 Tauri. I took continuous 10 second exposures around 00:56 am, while I watched the star through binoculars to see if there was an occultation by the asteroid below. Frustratingly, some high cloud drifted past just at the wrong minute, and made the star hard to see clearly, and it could well have disappeared for a second or so without me noticing. I was on the northern edge of the possible error limit of the occultation 'shadow' and as was likely, saw no disappearance of the star. After reviewing the camera shots there was no noticeable dimming of the star on 'film', but of course, it could have disappeared between shots. Also, unusually, during the crucial minute, some chatty cyclists came by. This disturbed me to look away from the binoculars and then I had to refind the star, so I can't say for sure it didn't disappear! Here's a picture with 14 Tauri labelled. It is quite impressive that Flamsteed could see this star without optical aid.

Monday, 1 February 2010

Asteroid occults 6m star...tonight! (Feb 2)

Just a one-off alert for astronomers across UK to test the accuracy of this little asteroid's orbit. (no picture, sorry!)
1248 Jugurtha, mag 14.6 astreroid will rapidly obliterate the light from the sixth magnitude star 14 Tauri (HIP 17408), which is just below the Pleiades. The event will occur at about 12:56 a.m to a few select areas across Wales, the Midlands, and East Anglia, possibly including London.

Friday, 22 January 2010

NGC 2683

There is no name for this galaxy as far as I know, but I discovered it on a sky ramble once with my 8" SCT just north of the constellation Cancer the crab. It was close to a little asterism in the shape of a kite. It sounds weird, but I thought of it as the crab-kite galaxy. I drew a lovely sketch of it, but now I have finally had the opportunity to take a piccy of it and even better, the picture shows a subtle texture detail. It is a lovely near edge-on galaxy, which always looks pleasing, with a subtle blue hint and other subtle splodges of colour towards the centre. There's even 2 little galaxies hiding near it! One of them being the 16.5 mag PGC 24945 (L). It's quite an overlooked galaxy because it's as bright as the brightest members of the Virgo cluster, but living isolated on the southern border of Lynx, it gets missed. It's surprisingly easy to find - just look for 'the kite' at the northern edge of Cancer, north of the star iota Cancri. It is 1ºN of sigma Cancri.

Eclipse to see out the decade

I tested out my new christmas present - a tripod with an old 400mm lens on my EOS. On new year's eve, I hopped outside my door and waited for the clouds to part, which they obligingly did to reveal a moon in mid partial eclipse. I spent quite some time squatting, craning my neck and shivering in the freezing cold. This picture was taken at 19:16 UT on 31/12/2009. I found the optimal ISO setting to be 400, because I closed the aperture to about f/18 for better focus and I stacked 4 short exposures. I enhanced the contrast to push the brightest spots to full brightness, and the moon starts to get lost in the umbra, so it appears fully black. This eclipse shows the range of brightnesses across the penumbra and shows the fuzziness of the shadow of the earth, caused by the half-degree angular size of the sun.

Wednesday, 20 January 2010

Pea in a haystack

Here's a strange one for you. A little green nebula right next to one of Messier's largest clusters, M34 in Perseus. It appears that some of the stars associated with the cluster have spilled on to my image of Abell 4 here, as it is dusted with some quite evenly-bright and evenly-spaced stars. When you've got access to a 20" scope, you should try out the Abell planetary nebulae if you want a challenge. I was blessed with a clear night so I used it wisely. PS Spot the galaxies.


Here is my picture of "the god of war", Mars, on the day after boxing day. It was taken the same night as the antennae pics below. An unusually still night and the planet was quite high in the sky. It turned out that it was only 12" across. I stacked 20 large jpegs on the Canon 350D at f/4.8 on the 20" (fl=2400mm) at ISO 100 and 1/800" exposures. I have blown up the pixels 4 x for comfortable viewing. I also took 20 raw-format pictures, converted them and stacked all 40 and got a slightly less pleasing result. I probably should have known how to use registax better and selected just the best few.

Friday, 15 January 2010

Lonely ball of stars

Having had that adventurous astronomical thought "where will I explore next?" I recalled a guest speaker mentioning the Intergalactic Wanderer. It is a lonely globular cluster, NGC 2419 in Lynx. It can be found by going a little way north of the star Castor, and it is just 10.4 magnitude and 6.2 arcminutes across, because it is more than a quarter of a million light years away in deep space. That means it is many times further away than any of those stars in the photo. The view of our galaxy from within the cluster would be pretty stunning but not like you'd imagine from sci-fi films. It would be something like our view of Andromeda but 10 times larger. This picture comes to you via the stacking and processing of 15 x 10 second exposures on the 20-inch at ISO 1600 and f/3.

V838 Monocerotis

V838 Mon is a star that went extremely bright for a few days in early 2002. Usually 16th magnitude, it reached 6.75 magnitude. At a distance of > 6 kpc this made it temporarily the brightest star in the Milky Way. Astronomers noticed a few days after it had faded that there was a brightening in the infrared. It turned out this was a light echo from the surrounding interstellar matter. You can google 'light echo' or 'V838 Mon' and you may well be familiar with the set of Hubble pictures, taken during successive months. Well, I thought I would try and hunt it down and see how it was doing. Not a lot. Never mind. That's mostly what happens in the universe.