in the wee hours

I got an early look at the dark, spring sky the other night. I went down to the observatory at 2am. This was the only non-moonlit clear free period I have had where it has been safe to travel, i.e. above 0ºC, just. I got the scope ready well before the moon set at 3am. It is a better time to observe, because a few people will actually turn their lights off and headlights become very scarce. Although there were a few flashes of lightning and a little mistiness to the upper atmosphere it was pretty still air and Mars looked surprisingly detailed, with 2 surface features visible and a lighter polar region. When I looked it up, the diameter was only 12"! However, as per usual, the scope did not track well enough for photography. I was getting nice 1/800" ISO 100 pics of Mars, but when it came to long exposures the wobble looked terrible. I had a quiet* battle with the tracking for a couple of hours until during an ascending slew, the declination motor decided to scream and stall on me (* the motors actually make a loud, quirky, metallic noise while tracking). After a gentle push, I found that a bit of weight on the scope helped.

By this time, the constellations Crater and Corvus (the cup and the crow) were up in the south. Scanning my cerebral databases I headed towards the Antennae galaxies. So here is my picture. Taken around 5 am, about 24 reasonably tracked pics of the Antennae galaxies (NGC 4038 and NGC 4039), at 30" exposure, ISO 1600, f/3(ish), stacked, processed and tweaked. It's a fascinating object and the word 'object' is a bit of an understatement. The faint 'antennae' are stars flung out by the combined gravitational interaction of the merging galaxies' stars. In the centre of the galaxies there are bright patches that are zones of star birth triggered by gravitational shockwaves in the material, brought about by the galactic collision. To reveal the antennae was well worth putting up with the freezing wind blowing on my face for 5 hours.

Frosty cloud

I haven't been able to get to my observatory despite some lovely clear skies! Ice and Snow, minus 4, minus 5... Oh well, even if I did make it the light pollution is 10 times worse because the snow reflects street lights up into the sky. Plus I'm saving petrol (carbon). I created this misty effect by building a mask using the luminance value, inverting it and applying a 5 pixel gaussian blur. Any guesses as to what this mystery object is? (Hint: there's an easy way to cheat).

The Geminid Meteor Shower

I caught a Geminid on film during the mostly cloudy night of Sunday the 13th of December. It's a game of luck to get meteors on film. During my imaging stint, which comprised of exposing a camera on a tripod, I saw several Geminid meteors. But only on the way back home at about 00:30 I saw a beautiful green firework shooting slowly down to the east. Through thin cloud, this thing was amazingly bright, it must have been about mag -4. The one I got in this photo I didn't see - it is the only one I got out in about 30 photos! It'a a bit rubbish, but there was plenty of activity and I thought I would 'report' it on this blog.

Eris 2

Here's the second pic of the animation as it doesn't work.

New record for the Society's 20" telescope

Being able to image the solar system's faint outer moons Triton, Hyperion, Phoebe has whet my appetite for obscure astronomical targets. I set to work looking for the solar system's outermost visible object, Eris (I still liked the name 'Xena' better). Eris is 96.7 astronomical units away. This is a crazy distance! Three times that of Pluto. It's therefore receiving 1/9th the light, and only 1/9th of THAT light will get back to Earth. This object really pushed the limits of my imaging system. This comprises of stepper motors, worm gears, an MS-DOS program, an Alt-az hand built Newtonian telescope, a field flattener and a Canon EOS 350D (at about 8ºC). The site is now fairly light-polluted but we have a dome. Eris was about 30 degrees up in the South when these images were taken (13 days apart). It has only moved a few arc minutes (mostly parallax shift) in this time because it is so far away and that is how it evaded detection before Jan 2005. It has a moon, Dysnomia, discovered Oct 2005. Using the moon to 'weigh' Eris, it is now known to be more massive and also larger than Pluto, thanks to Hubble's impressive measurement of its size. I really had to optimise the stacking and processing of each of these images. The second image (Eris on right) is noisier, despite more (43 (cf. 32)) 30 second images. These are cropped and put together into an animated gif.

See "littlebeck" blog on my links - for the necessary images that reassured me that my blobs were Eris.

Art stolen from the sky

This is the current most wonderful piece of art I have stolen from the sky. It has a happy, pleasing quality about it. I can’t say why. Maybe it’s because it’s just pretty, or it’s because of the sheer otherworldliness of it. For instance, that bizarre Y in the middle. I enjoy the slight imbalance of the picture, it was intentionally cropped that way. The dark blobs on the right are made so much more interesting. Behind them is a little pocket of pink glow trying to shine around the edge. The two blue stars at the bottom are like incisors. They are top 2 of a little cluster of stars far out to the east of Orion. That cluster is the way to find the Rosette Nebula, which encircles them and is much bigger than I can fit on my pictures. I suppose I could pan around the area and get lots of images, but I haven’t come across a way of making seamless mosaics yet as in my opinion Canon’s Photo Stitch does a pretty clumsy job, especially for space art. I write this with appropriate ambient background music on: you could feel the sky, on geogaddi by the Boards of Canada. Definitely a case of the old adage ‘a picture paints a thousand words’ so I shall stop now!

The Pac-man Nebula

This is a significantly shaped cloud of glowing gas.

M33

Here’s my latest picture of M33 on the society’s 20" scope; an improvement on the higher res. mosaic in terms of smoothness and aesthetic appeal. I just managed to squeeze it into the field of view using the Meade focal reducer lenses and tilting the camera. It’s quite surprising that this galaxy is the size of the moon. It is one of those vast celestial objects on the dark shores of the world visible to human eyes. Its visibility is strongly dependent on the sky transparency and the scattering level of light pollution. I’ve never seen it with my bare eyes, only the nearby cluster NGC 752, although it only takes the tiniest telescope to see M33. Big telescopes will reveal very subtle patches of brightness within its spiral arms. In other words, it really looks nothing like the photograph. To the lower left of centre is a HUGE nebula many, many times larger than our Galaxy’s Orion Nebula that has its own New General Catalogue entry.

Nuisance lighting

Industrial estates, some farms, large houses and gardens near the observatory seem to be pumping out wasteful amounts of light all night with only the cost of electricity to deter them. Where is the respect to nature and the environment? It’s high time to raise awareness of this issue, give encouragement to switch off or angle lights downward, or to start enforcing rules preventing light trespass and waste. With regard to security lighting… does the light really make the place more secure? At the observatory I prefer to leave the outside light sensor off to hinder would-be burglars being able to see what they’re doing. Studies (CfDS) already show that lights do little for crime prevention. The steady increase in lights filling in all the remaining dark spaces on the countryside map now includes lights that can leave a bright spot in your eyes from a distance of half a mile. To me these look at least 500 Watts per light. They include a certain “farm” on the Watton road and some ridiculously dazzling construction lights on the A11. Worst of all is Wymondham industrial estate – what a horrific waste. I am pleased that by pure luck the light on the industrial estate near me has just been removed. That one casted eerie enlarged shadows of passers by across my door! The picture above is of the school beside the observatory - who for some reason left their lights rudely shining across to the observatory’s al fresco telescope area.

Sun Dog

I rediscovered this picture of a parhelion or ‘Sun Dog’ on some beautiful wispy, icy clouds. It looks like it was taken some time in spring based on the position of the sun. This optical phenomenon is caused by flat hexagonal ice crystals refracting sunlight by 22º. The effect can also cause a halo at this distance from the sun, and even the moon. Light dramatically reflects off the ghostly swirls above it and the contrast in the background blues makes a lovely composition.

A galaxy...in just 2 minutes

Here’s a picture of M81, a galaxy similar in size to our own Milky Way, 12 million light years away in Ursa Major. It is also known as Bode’s Nebula as it was discovered before the idea of galaxies outside of our own. I got this wonderful final image with just four 30 second exposures at ISO1600 & f/3. It’s processed in a non-linear way with boosted contrast between the faint spiral arms and sky background, and also to show some detail in the dust lanes around the centre. In fact I have blackened the sky which was its usual muddy brown colour. Visually, through a telescope, it appears to me as a bright central nucleus surrounded by a hazy ellipse. The spiral arms are too faint to see so the full size is not visible. Very near by in the sky is M82, a galaxy showing lots of structure but I always find tracking down M81 a bit tricky.

Big scope peers into the depths of our spiral arms

Abell 20 is a faint planetary nebula in Canis Minor near Monoceros, which is nearly as wide from our perspective as the beautiful Ring nebula in Lyra. The main difference is that this one is about magnitude 14.7, nearly 6 magnitudes fainter and only 1/200 th as bright! It needs a hefty telescope like our 20” to help gather and capture its elusive photons, most of which are a delightful turquoise shade of doubly-ionised oxygen. The central star looks quite busy but only appears so from our distant vantage point. It is magnitude 16.5. Apologies for what looks like green rain falling diagonally across the picture. It is an artefact of some detrailing I did and the over-processing required to see the “faint fuzzy”.

Gassy young stars

This is me peering deeply into the Pleiades cluster. So deep, even with my field widener attachment, that I could only see two of the stars within the cluster. And this field is 40 arc minutes across. Now, obviously, this isn’t a properly deep picture, like you would see in some expensive CCD camera advert (that doesn’t give a price), or a magazine pic of the week. But to me it is deep, because it shows lots of blue clouds floating about between the stars, reflecting their spectrally blue cosmic light. It wasn’t a long, or particularly well tracked set of camera exposures, but it’s the subject I’m interested in, and my aim is to maximise the aesthetic appeal of the final picture. Contributing to that appeal is a particularly quirky set of flare lines coming off the star Alcyone at the left that provides a skewed detail to the picture. The streaky nebula at centre is named after the star, Merope which is only 30% as bright as Alcyone.

Messin' with filters

Lumicon’s 1 ¼" UHC filter is a superb addition to my visual astronomy toolkit. I’ve seen the stringy, fluorescent shockwaves of the supernova remnant in Cygnus, the North America nebula, and now I have faintly seen the glow behind the horse head nebula. But for photography it is a bit disappointing. The light is mostly rejected - it seems to be too narrowband for good imaging and the light really should be collimated first for it to block the correct wavelengths. I can’t quite work out why the photographic result should be so different to the visual experience at the eyepiece. Any comments welcome. I did 5 exposures that tested the tracking of the 20” scope (60-90 seconds each). Detrailing, stacking and processing resulted in this faint but fairly decent picture of the Horse head nebula's Hydrogen Beta (H-β, λ = 486.1342 nm) emission.

Out of this world (literally)

This oddity is where astronomy and art mix.
I wonder if you know what this thing is?
I'll say no more than that this area
of sky intrigues me - what a cosmic field...

Hind's Variable Nebula

Here is one of the other less studied variable nebulae -
Hind's Variable Nebula. There are a lot of very, very faintly glowing clouds surrounding the whole lower half of the picture, but the clouds certainly aren't picked up in this image. So don't go scrutinising it too deeply - instead you can see the void in stars blocked out by dust. The star at the centre is T Tauri, the prototype of its own star class. To me it looks like the starlight is reflecting off a hidden, dark wall of dust to the right (of course there is no 'right' in space!). I thought I would slowly slew the big 20" scope to this nebula near the Hyades and get a few minutes worth of exposure in order to follow on from Gyulbudaghian's nebula (see earlier posts). Unfortunately it was quite low in the direction of a small town, which means it is impossible to cut through the light pollution and get a deep image. Still, I got my first look of it in the eyepiece.

Another instance where a pair of tights comes in handy

Let me explain the title. At the observatory we were discussing how to get some real scientific measurements out of our telescope. It so happened that our expert former-professional astronomer and author member was there and he suggested that we could record the spectra of stars. For this purpose, we have a cardboard circular attachment with what looks like tights material streched over it, which velcros onto the front of the telescope. This is actually a clever but rudimentary diffraction grating that splits some of the light from stars into spectra that radiate out from them. We spent a while looking at bright stars and seeing rainbow starbursts all around them! However, we couldn't make out any colours in the outer spectra as they were just too dark. Our former-pro must have had unique eyes as he could see colour all the way out. At this point I got rather inspired, as I had once looked at a mysterious object called "Campbell's Hydrogen Star". It was an ordinary star to me at the time, except that it didn't disappear when I put a nebula filter in the eyepiece. Here is an image of that object (147"@ISO1600, f=2400mm f/4.8) and its spectrum which I have specially processed by cloning the image, rotating 180º & excluding anything that didn't match, thus highlighting only the spectrum of the object.

Campbell's star is a bright (9m) but very small (5") planetary nebula 2.5º north of the star Albireo, that went undiscovered until the invention of the spectroscope. It has a strong emission of hydrogen lines (see the red, blue, violet bands in the spectrum). Also there is some emission in the middle of the spectrum, presumably from the central star (11m). Maybe a messy picture, but pretty good for a pair of tights.

Northumberland Astro Soc.

Having travelled from Norfolk all the way to North of Newcastle, I got an extremely warm welcome by a friendly bunch of people at the Northumberland Astronomy Society (and free entry and a cup of coffee!). It was a Saturday, there was an entertaining open night talk by a Mr. Jannetta, to the point where it seemed like he had control of the heavens. It was a sharp and clear dusk over Hauxley, near Amble, and we had a nature reserve shed/hide as the club room. This was absolutely ideal as it pointed South across a prettty tidal wetland with a beautifully low horizon- the preferred direction for astronomers! But the best bit was the talk stopped at about 8:13 p.m. and we all gathered along the long window to watch the now superbright International Space Station sail slowly from right to left and "above" the planet Jupiter, which we could also see reflected in the water below. I bobbed down for people behind me to see and I rested my DSLR on the windowsill and got this 2 second snap. The only inconvenience was that I had to try to get back to Leeds by 11 p.m which meant no observing!

The Crescent Nebula

This object is a splatter of red and blue paint flung out from a seething star. Here, the hot star's shed atmosphere is lit up by it's ultraviolet light and fluoresces in hydrogen light. The star is the 7.4 magnitude Wolf-Rayet star, PPM 84423 in the constellation of Cygnus. Just before I slotted the camera into the scope I got a stunning view of this strange arc. I used a 20mm wide-field eyepiece with a Lumicon Ultra High Contrast filter on the 20" telescope (f=2400mm). However, I didn't see the lovely colours shown here. The picture is 9 stacked 30 second exposures, plus flats and darks and the object is called NGC 6888, or the Crescent Nebula. I managed to dismantle my field flattener and insert the lenses into my camera adaptor to convert the f/4.8 scope into an f/3 scope a.k.a a 'light bucket'! The nebula can be found by aiming 1/3 of the way between the bright stars Sadr and Eta Cygni, and moving a tiny bit right. Look for the little W or M - the bright stars you can see in the lower portion of this picture.

Deeper still

Here's the latest 82 images of Gyulbudaghian's Variable nebula stacked with a more carefully taken flat field. Just thought I'd share it with you. Look around the red star PV Cephei in the dark 'hollow' at the centre - can you see a jet shooting out below and slightly to the right? This is the nebula I'm looking for - not the vast billowing clouds swallowing up the stars at the left. It's madly overexposed as I couldn't resist turning up the contrast!

Obscure Nebula - looking deeper

We had compared our images of Gyulbudaghian's Variable Nebula (HH 215, GM 1-29) and neither of us could see anything definate. It was the last deep-sky night for a fortnight as the moon was setting at 11pm as a distorted deep orange almond sinking behind the horizon. So, I was inspired to take another good bunch of 30" pics. All in all, I stacked 46 (including the previous pictures - below) to get a total exposure of over 25 minutes at f/4.8 on the 20" telescope. Here is the result. This picture is improved enough for you to see the Herbig-Haro jet HH 415 and the background nebulosity is clearer. HH 415 can be found by going below and slightly left of the bright blue star right of centre to find a bright-looking 13th magnitude star. There is a very faint star just below this and the object is the small streaky blur just below that. As for the main object around PV Cephei (just below centre), I still can't really see much there. With this picture, I increased the saturation, as it had somehow dropped during processing. So now the colours of the stars are revealed and they are stunning! This is especially useful on PV Cephei, which is clearly revealed to be a dim red colour, sitting in its dark patch of nebulous dust. Who knows what magnitude it's at now!?

The Helix Nebula

Contrary to what I've seen written, the Helix nebula is not the closest planetary nebula to us. It is one of my favourite objects but it is quite elusive, as it can only been seen at certain times under good conditions from UK and I had a good window of opportunity the other night. I took several shots, about 60 in all I think, 45 of which were good enough to stack (22x30",22x15" + 1'). The main trouble is that the nebula is so diffuse, it was barely visible on the individual pictures because of LIGHT POLLUTION! The worst culprits round here seem to be rural industry and carelessly aimed, wasteful and unnecessary security lights. So, to combat this, I stuck in a 40mm eyepiece on the 20" (60x) with a Lumicon UHC filter screwed on and the detail in the helix's structure was amazing and the centre of the nebula was filled in with a cool blue glow. I've done a lot of careful processing on the final image, as the flat fields were not as flat as I'd have liked (I took them on a white door indoors). It still looks quite noisy I think, but it's a beautiful object that I've been waiting a long while to photograph this well.

Gyulbudaghian's Variable Nebula

In this picture of Gyulbudaghian's nebula, North is down. It was ~ 8 mins worth of exposure on the 20" scope nearly overhead (5x1' + 6x30" + 17"). The nebula, which was discovered to be variable in 1977, has been very, very faint recently. The white lines point to the star PV Cephei, which is also faint. If you compare it to a previous image you will wonder what has happened to it... Strange star! (image courtesy STSci)

M19, the elongated globular cluster

Just a quick post to keep the blog ticking over. M19... A curiously elongated globular. One of my sharper images on the 20", but still a but fuzzy. I had to play around with the colour, as Deep Sky Stacker decided to give the midtones a green tinge when it stacked the pics. If I remember right, this was about 10 x 15 second shots on the 20", when it was tracking well, with darks and a flat. As far as globulars go this one is very close to and slightly further away than the centre of the galaxy, and we're looking at it through a plethora of distant stars and a bit of dust. It's an impressively big and bright cluster and it can be seen in binoculars at magnitude 6.8 in the constellation Ophiuchus. But why is it elongated? My instinct tells me it's tidal forces from the centre of the galaxy, but that's pure speculation.

Polar Mesospheric Clouds a long way South

On our observatory meeting night, we were treated to the usual clouding over and sprinkling of rain, while we were inside chatting. I was upstars in the dome, hoping we would be able to see a star or have something to point the scope at. We were watching a clear patch start to roll over revealing the twlinkly red star Antares and there were some cirrus-like clouds appearing right across the sky as the twlilight was fading at about 22:00 BST. I presumed they were cirrus but as the sky grew darker I realised they had some wonderful wave like patterns in them, and they continued to stand out from the darkening sky. They were Noctilucent clouds, covering the whole sky at 52 degrees North! I ran to the car while they faded to fetch my Canon 350D and took a few shots with it resting on a chair seat on the observatory roof, pointing NW. This particular shot taken at 22:36 on 15/07/09 is 1/5 second at ISO 1600, f/5.6 and about 35mm focal length (48mm @ 35mm-equivalent) with auto dark subtraction on. I continued at 4 seconds and ISO 100 thereafter for better noise, but the composition and scale of this earlier display looked the most impressive.

What was in front of the Space Station?

The Shuttle mission STS-127 has been delayed several days by bad weather, so what was the mystery object 30 seconds ahead of the International Space Station when it flew over Southern Britain at 23:07 UT(GMT) on 12/07/2009? Quite bright, it is clearly in the same orbit because the trails just appear to touch on this 30 second picture, as they did in the consecutive pictures. Take a look as it passed below Arcturus, viewed from just North of Norwich. Remember the light from the satellite has been spread out across its path and the ISS appeared much brighter than Arcturus.

Messier mosaic

Here is a 4x3 snippet of my new Messier object mosaic. Each picture is a 300x300 pixel image I have taken of the object. Some are awfully low in altitude from 52ºN. It's surprising how different each image is. Each have their own image processing challenges, whether it is light pollution subtraction, bringing out faint spiral arms, or eliminating the blurry disc effect on the small globular clusters. I learned that not all globulars look alike, and they all look impressive with a 20" scope. I used different magnifications for different objects, e.g. M24 in Sagittarius is huge! I have arranged my mosaic as 11 rows of 10, so each column ends in the same digit - but it's not complete. Here is a complete section so you can guess what columns and rows I have shown - if your astronomy knowledge is up to it, that is!

My best shot of Pluto yet

Pluto still has a place in our mind as a planet, but it's just too small. Smaller than the moon, a little bit brighter, but about 12,000 times further away. It is about 3,000,000,000 miles away in this photo and the light from the sun that's reached it is having to come all that way back in to us. It's amazing we can see it at all, because that light is the 'lucky' portion that has reflected almost straight off the rocks or ice on its surface. But nevertheless, it is clearly visible when you capture 30 seconds worth of those photons by bouncing them yet again off a 20 inch highly silvered mirror in a hole in a dome in a field in Norfolk. Pluto's moon, Charon, would also be visible if it didn't lie within the small circle of fuzz around the image of Pluto.

Hydrogen Balmer α

Apologies for not blogging for so long. I blame the summer twilight, and my new project. Since I got a reasonable picture of M83 (not the best of pictures - see below) I realised I could produce my own Messier mosaic. Unfortunatetly, this will take me the best part of a year, because I started in May. However, I am nearly there with the images - I have well over 90 of the 110 now and it's looking good. So I thought I would see what pictures I have that I am more pleased with. One of those I took last year with a single hand-guided exposure of about 6 minutes through a 400mm f/6.3 lens onto Kodak Elite Chrome 200 film. This was scanned directly from the slide film by Mike B, a much, much better quality scan than the crude messy job I paid the commercial photo processors to do. The field encompasses the star Sadr in Cygnus, M29, plenty of nebulosity and clearly shows the Crescent nebula - you can use it as a chart how to look for it. So here I've attached a higher quality *.bmp file for your perusal. As you can see from my previous images the Canon EOS's filtered sensor isn't a match for even ISO 200 film at the wavelength of Hydrogen Balmer α emission, 656 nm. Seriously want a modified one, but serious lack of £££!

An example of what a good 'flat' can do

I've decided to do my own collection of Messier object photos. Here is a photo of an object that I can barely see from my home latitude of 52.6ºN - M83, the Southern Pinwheel. It's 8.3 magnitude, but Declination 30ºS. Easily visible from latitudes such as Paris, Rome, New York, but venture back northward to the UK and it disappears into the murky brown skies we have here. It barely rises above the south horizon. When I took this photo it was about 6º up. (I also managed to get Ptolemy's cluster, M7 this night too!). Fortunately the observatory dome has a beautiful flat horizon, only spoilt by distant light pollution, which was exacerbated by moisture in the atmosphere after a hot, sunny day. During the long summer evening twilight, I managed to capture 10 flat field frames in a blank spot near Capella (at ~40% pixel saturation level) and thereafter I took 10 dark flat frames. So armed with a smooth flat I took 3x10", then a 20", followed by 16x30" exposures of M83, which individually looked like a yellowish blurry star on an intensely reddish brown background. I later got 4x30" dark frames. I spent the whole of the next day trying to stack them, but had to shrink each image by 50% so Deep Sky Stacker would pick up the stars, but once I did that, at 1 o'clock the following morning, the spiral arms finally revealed themselves! It definately needed the 16-bit image processing in DSS. After a quick cross-check using Starry Night Pro, I'd picked up PGC 48132, a 16.0 mag galaxy, which is just to the left, inside from 2 x 12 mag stars. What an achievement!

Lunar halo

While on my ante-meridional astronomical expedition I had the fortune to watch the gibbous moon setting behind cirrus cloud, creating a delicious opportunity for a lovely composition of a lunar 22º halo with stars above it and a very early, subtle dawn glow. Can you spot any constellations? Details: ISO 1600, 20s, 28mm f/2.8 + fish eye, rotated, cropped & colour balanced.

Good old summer sky coming back around

I recently did a midnight-'til-dawn astrononomy expedition to my solitary coastal heathland spot and saw all of those lovely summer delights at the milky way centre slowly rising in the south-east. So, I thought I would put a bit of effort into manual off-axis guiding. This involves me bent over looking at an extremely faint guide star and trying to keep it on the red crosshairs using a N/S/E/W hand pad. After the 30 second pictures started trailing because the automatic tracking was slowing, I got a 3 min 45 second picture of the Eagle Nebula, M16. I also took some 30 second darks, flats, flat darks, a 4 min dark, which roughly offset the internal camera 'glow' from the Eagle Nebula picture. After applying all the flat corrections I found my image much noisier than the raw image minus the dark. So here it is: a single exposure at f/6.3 f=1260mm 1600ISO (my manual guiding skills are great). I have used the vignetting (central brightness) to my advantage during the processing. The 'Pillars of Creation' are in the middle of the red nebula just to the right of the open cluster. An improvement on last year's multiple 30" exposures, and a surprising amount of red!

A Whale?

At last I've processed my folder full of pictures I called 'galaxy madness'. There's a whole lot of galaxies you can see and a whole lot more you can photograph with a 20" telescope on a good night in spring. Here's a funny one I found in the funny sounding constellation Canes Venatici. I detrailed and stacked 22 x 30second images of it (f/4.8, f.l=2400mm) so the exposure was 11 minutes on my Canon EOS 350D. It's an amazing likeness, n'est-ce pas?

20" vs 8"

This is the same subject as in the last photo, the Owl nebula, M97, in Ursa Major. I popped over to the observatory and took about 80 x 15s shots of the nebula through the 20" newtonian, which I could barely see through the camera after focusing on Merak. The telescope was descending from the zenith to the west. Most of the images were trailed because of poor consistency of the motor tracking and a good few were slightly spoiled because of car headlights on main beam shining right into the dome. Who's fault is this? The ridiculous number of cars on a tiny road at midnight or the observatory siting? We could do with a big sign to block the lights out. The bright moon made the background light subtraction most difficult, as it gave a subtle gradient across the picture that when processed becomes more severe. I whacked all 80 RAW picture files into Deep Sky Stacker and after about half an hour while I watched the Sky at Night, it had stacked them into one image with 8 minutes' worth of exposure (32 pics). Just look at the difference from my windswept 8" f/6.3 Schmidt-Cassegrain image on the post below. I couldn't track for as long, but the f/4.8 (fast) optics, good focus and massive aperture really helped bring out the triangle of 15th mag (ish) stars in the nebula. You can even see a couple of galaxies if you look carefully to the left and upper left of the nebula and the reddish outer edge of the nebula is just perceptible. (image repeated for comparison with below)

The Green Owl

We had a pretty display of stars from the city the other day; a clear, transparent night seemed to be underway so I got my 8" SCT out and drove up to the middle of a dark heath with a view over the sea. Fantastic! The light from the north came more from the milky way looming in the background, stationary above the sea. There was an aurora-esque shaft of light shooting out at right angles across the constellation Cepheus. A few dark clouds were actually sillhouetted against the milky way background. Ursa Major was approaching over head and I pointed the scope to it, attached my camera, focused, but the strong, cold wind was blowing the stars into little fuzzy flower shapes. I removed the dew shield, knowing that the wind would look after any condensation and set to work with a few 1 minute long snaps of the Owl Nebula, M97. Half way thorough, I ended up changing the 9V battery for my motor, and trying to repair a broken wire that has broken under field conditions like that was not nice. I spent ages trying to get Deep Sky Stacker to recognise my fuzzy stars but it was useless - I forced it to stack 16 in the end (which I had individually modified) and then it gave me stupidly blue pictures. I spent an equal age trying to work with Registax and I processed in Paint Shop Pro. The pic here is the 16 x 1 min Deep Sky Stack, ISO 1600. Apologies for the slightly yellow stars. You can see the Owl's eyes and central star. The Owl nebula, M97 is a 3' wide, 12th magnitude planetary nebula near the tip of The Plough.

Venus sweeps inside Earth's orbit

On approach to 'inferior conjunction' Venus is now a large, thin crescent, oriented horizontally - a rather strange angle for such northern latitudes and disappearing rapidly into the twilight. I dashed out to a local field with my brother and got about 40 very rapid snaps straight down my 8" SCT using a 2x barlow lens (f.l. ~ 3.9m). It's amazing how bright it still was considering how thin the crescent phase was, which by the way was easily seen in 10x binoculars and not quite by eye. I could see a fine backlit lower edge to the globe at 200x, seething in the low atmospheric turbulence and its brilliant white colour was dispersed into a near perfect spectrum. I stacked the best 17 of the 1/500" pictures (ISO 1600) and got a beautifully smooth rainbow crescent. Whilst this looked wonderful I had to use the RGB realign tool in Registax to shift the blue down and red up by 8 pixels to get a much sharper white crescent. Here's the final imaged cropped to a 500x500 bitmap.

Lulin encounters the Eskimo

Popped down to the observatory tonight as the weather was virtually promised to be clear. I had to walk past a load of kids getting up to dodgy things in the village hall car park as they had parked in the way of the gate to the observatory field. I don't mind 'club' music but there was some boring but extremely loud, monotonous, repetitive rave music coming from the hall where they were all gathered outside, smoking. Still, they were no bother, the moon was out of the sky, the floodlights weren't on - the only problem was the large amount of passing cloud the weathermen hadn't predicted again - the liars! (about 5 'octas' worth, I believe). I could see the constellation Gemini, which is where the comet Lulin was currently sailing as it was quite near overhead. The scope worked fine, I got lucky with several clear patches and captured 6x30second pics of the comet, but then I realised the comet was very near the Eskimo or Clown nebula. I squeezed both into one camera field at a push and got 3 shots - and thought this was much more worthy of a blog entry. The nebula is slightly overexposed, but it was a balancing act to process. I've included the Lulin shot also, processed to see the tail. I put the telescope to sleep (as we say) and got straight out and straight home in good time for bed for once (not that I have gone to bed, I am an astronomer after all).

The butterfly nebula in the constellation of the unicorn

I pushed the processing of this little planetary nebula (NGC 2346) until I could just see the wing shapes around it, that give it the name of the butterfly nebula. It was not obvious to see visually, although there was definately a bluish haze around the central star. This star is a spectroscopic binary, and is variable - possibly due to dust orbiting around the pair every 16 days. The dust could also explain the infra-red emission. I thought I'd give you a wide field shot; 20' x 30' is the raw field from the 20" scope and I took 8 x 15 second pictures at ISO 1600 on the Canon EOS 350D.

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).

Leo I

With this title I am not referring to the papacy, but the local dwarf galaxy near the star Regulus, which I was thrilled to pick up on this photo. Not a fantastically sharp picture, like some of those all-nighters on the internet, but artistically composed let's say. Those dedicated astrophotographers are blessed with fantastically dark non-misty skies and $1000s worth of equipment, whereas I have UK weather, UK light pollution, a hand made scope, a reconditioned D-SLR and little patience. There is also a 14th magnitude galaxy at the bottom - North is right on this pic. It was 6 x 30 second RAW images converted to TIFs, detrailed and then stacked in DSS (apologies for all the TLAs).

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).

Sol

I looked out of my window this morning and saw unexpected whiteness everywhere. There was no snow forecast, it was just a deep, powdery frost. So I went to my local heath to take some photos and as I climbed the hill I turned back and it was one of those rare occasions when you can look straight at the sun. It was wierd, like looking at a blank, white moon and I gave it a good stare, but I couldn't see any sunspots. I bracketed the exposures but chose the 1/2500" on ISO 100 with the Canon standard lens zoomed in to 70mm. This picture is a crop of a high quality jpeg and the optical quality is amazing, so I couldn't bear to scale the picture down (as I do for all the space pictures that overexpose stars into huge blobs). It was -4º with a breeze and I had no gloves, so in no time I had immobile hands and the autofocus frosted over.

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

Blogger just lost my post because my finger accidentally fell on to the laptop touch-pad and clicked back on the browser! When I went forward again it was blank and so was the saved draft! Has anything similar happened to you? Anyway, enough ranting, here I present NGC 672 and IC 1727, and even a red galaxy PGC 1803573, which Andrew found out for me - the guy who does the 'littlebeck' blog. Can you see that the galaxy on the right, IC 1727 is a distorted former barred-spiral?

Cosmic Keyhole

This nebula is pretty easy to find - it is just below the Orion Nebula. NGC 1999, or the Keyhole nebula, for obvious reasons. It is quite striking in appearance due to the cloud of cold, dark 'dust' blocking the lit clouds behind. It is a reflection nebula, so I tried to process it to bring out all the faint outer nebulosity. Visually, it didn't look like much: just a smudge around a faint star, even in the 20" scope.