Monday, 26 December 2011
More delights of Orion
The chocolate box of Orion contains a selection of objects from visible to photographic beauties. The area around Alnitak (ζ Orionis) is particularly striking with a good telephoto lens. This particular lens has produced a couple of new nebulae via internal starlight reflections. The spike at top left is Alnilam trying to peek into the edge of the shot. I piggybacked my modified 1000D camera on the club's 9 1/4" scope on a CG5 mount and without guiding, got some 2 minute exposures through an old f/6.3 400mm lens. The RA drive had a wobble with a 10 minute period, causing most of the pics to be slightly trailed, but I managed to stack 12 of them with a combining method that minimised trails. So, here I present 24 minutes of exposure centred on the dark cloud called the Horsehead nebula B33, which protrudes against the hydrogen-red background of IC 434. The blue reflection nebulae NGC 2023 and IC435 can be seen below the horse, shining from within the sooty cloud. The more yellow or pinkish Flame nebula, NGC 2024, appears attached to the other side of Alnitak, and this can be seen, albeit dimly, in telescopes much more easily than IC 434. The grapefruit like colour tells us that it is not exclusively shining in hydrogen red light and there must be some cosmic dust scattering component to its colour, rendering it visible to human night vision.
Labels:
B33,
Flame Nebula.,
Horsehead nebula,
IC 434,
IC435,
NGC 2023,
NGC 2024
Thursday, 22 December 2011
The Perseus Cloud
A dim patch of light emerges from the dark cloud in southern Perseus. This is NGC 1333. I thought I'd have a second try at this object with my modified camera on the 20". I had a good dark night when the object was quite high and plenty of light gathering power. It was a bit of a struggle getting good auto-guiding, as it is a dark cloud and there are not many bright stars nearby to guide on. I did a bit of masking and selectively blurring the dim nebulosity, in order to try to smooth out the background, but started to get into 8-bit processing artefacts. In the final image (33 x 30second & darks, flats, etc.), reddened stars abound in the dark cloud, and the blue reflection nebulosity fades into the darkness around the edges. A few dark lanes cross the nebula and a few spots of activity show up dotted off to one edge. The large dark cloud crosses the centre of the image and background stars appear to peek out to the right edge. The width of this picture is similar to that of the moon.
Wednesday, 21 December 2011
Breckland Skies in Winter
I love the return of these beautiful constellations on freezing cold nights. It was dropping well below freezing and as I looked south out of the dome at Breckland Astronomical Society I could see stars right down to the horizon. There was one star especially low down below the constellation Lepus, which I recognised as Pheat, from Columba the Dove. I couldn't see the other two stars near it - but I grabbed the Canon and gorilla pod and clamped it onto the edge of the dome, pointing south. I found I could fit in all of Canis Major and Orion with the standard lens set to wide. I processed to reduce a bit of the background glow, but it was much stronger towards the horizon. An odd cloud was floating through Columba, which I could see. It wasn't moving fast, and appeared pretty small, but it managed to smear out on this image. There were a few high clouds drifting by which I could only see on the photographs. The camera managed 21 good 15 second shots before the battery ran out of juice in the cold and I stacked them in Deep Sky Stacker. Hence the motion blur across the southern horizon. If you look closely you can see the red R Leporis off the upper right of the main pattern of Lepus, next to a whiter star for comparison. I have not processed to show the Rosette, Horsehead, Flame and Orion nebula.
Saturday, 3 December 2011
NGC 40
Here's a pretty little stellar remnant that's visible in average telescopes most of the year from the UK. NGC 40, which can be found in Northern Cepheus, shows up very red on film, but is blue in appearance even in large telescopes. Due to this bright redness it shows up very quickly on camera. I got a handful of pictures of 30 second duration, some 10 second and some 3 second, stacked them, then averaged and sharpened them. I think it looks quite a flowery little nebula.
Thursday, 1 December 2011
The Intergalactic Wanderer
The intergalactic wanderer (NGC 2419) is actually not wandering. It is in a 3 billion year orbit around the Milky Way, which takes it further away than the Magellanic Clouds. It's currently 275 000 ly from us and 300 000 ly from the milky way's centre. I remember reading some notes in"Cirque du Ciel" (actually Cartes du Ciel) that the individual stars are 17th magnitude. Some facts about it don't square with me. I read that this globular is huge, and compares to omega centari (see recent posts), which has millions of stars. It is intrinsically very bright in total and appears as a 9th magnitude fuzz in the scope. But the individual stars must be 17 or so magnitudes below that (because 17 magnitudes = a factor of 6.3 million in brightness), more like 26th mag. Perhaps there is a huge range of brightnesses and the brightest ones around 17th magnitude. It is a big, big thing a long, long way away in any case! I wonder if it can sense the dark matter halo? The cluster lies in the direction of Lynx, near the twin stars Castor and Pollux from our humble perspective. I did a colour blur on this image and upped the saturation, sharpened a bit to make it all pretty. I suspect the colour went a little bit crazy along the way, but I love those colourful, spiky starbursts.
Spooky, Nebulous Fingers.
WE pointed the twenty inch at the Eastern Sky, so we could get a nice long exposure without rotation. Rising nice and high is the constellation Auriga, the charioteer, and in its centre lie some interesting patches of nebulosity. The "spooky, nebulous fingers" in this photo are otherwise known as the central part of IC405. There's a nice bright guide star here for us. I got 30 minutes worth of luminance, colour and dark images, using the Atik at -20 C, binning 3x3. I stacked in MaximDL then processed by blurring the colour frames, aligning and colour combining. An auto flat overdid things, so I averaged the autoflat corrected frame with a copy of the uncorrected frame. Next, I ran Digital Development and liked the contrasty effect, so I did the same thing with this. I couldn't mamange to get bright colours, they just don't seem to be there in this object. I think nebula filters Ha OIII Hb are the way to go! I did a small manual detrail using 'layers' and 'darken' on it to get round stars. This object is also somewhere in my past blog. Hopefully this pic is an improvement.
Thursday, 24 November 2011
The Lagoon and The Trifid Nebulae
Four 5 minute exposures of a favourite region of sky of astronomers was enough to produce this wonderfully colourful and stunning scene. The Lagoon nebula (Messier 8) is below centre, and you can see red hydrogen gas extending out to the left of it. Around that is a dark, twisty channel, with some strange tight turns. That is in turn blocking out the light from the myriad stars of the central milky way in the background. A short hop celestially north lies the trifid nebula (M20), which shows its beautiful colour contrast, and the star cluster M21 appears above that. The darkness to the right is merely apparent due to the blocking of star light by tiny aggregations of molecules, spread thinly, but over such a large volume they collectively cut out virtually all what we see. Other wavelengths of radiation, such as infra red, can shine through these clouds. The 'visible' wavelengths between 0.4 and 0.7 μm were captured with a Canon 1000D with the nearIR-red filter removed, through a Sigma telephoto zoom lens at focal length ~ 300mm, on a well aligned Astrotrak.
Nebulae in Norma
When I was collecting my stellar photons from those sparkly, southern skies last summer I rushed back into my little warm chalet to process the photos. I discovered a new nebula in Norma! Well it had been there all along, but I like to think that. It's a personal discovery. It looks like a swooping giant bird. Apparently it is called NGC 6188, and there is another planetary like nebula towards its north west (upper right), which appears as a fuzzy star on my poor resolution picture. You can see zeta Scorpii at the top, along with another one of my personal discoveries, namely a big faint red patchy ring around the whole cluster. Actually come to think of it, the whole picture is teaming with my new 'personal' discoveries. Dark, straight lines. Who said nature doesn't like straight lines? a physics teacher? Well my last few years of astrophotography have shown me many rows of stars in lines that are too straight to be chance alignments. There are a sequence of giant (I mean HUGE and capitalisation of the letters really is quite an understatement), dark, frigid clouds across the picture. Also, there seems to be a tinge more redness down towards where the tree has made its impression on the moving stack of photos that went into producing this image, but that could easily be an artefact of the processing. The atmopheric extinction of starlight shows up with the lack of light pollution, at such high contrast.
The void
Sorry for not posting for a short while. I've been looking into the void. Unfortunately, I was aiming for the diffuse irregular galaxy IC 1613 in Cetus (/Pisces) and I synchronised the telescope on the wrong star. It wasn't far away, but instead I got an 11 minute picture of the star Hipparcos 5166 and the brightest object of interest in the field was a distant 16.88(blue) magnitude galaxy NPM1G+02.0042 . I haven't even heard of that catalog. I decided to look up the galaxy on deep sky browser (http://www.messier45.com/). That's what you get when you look in the wrong direction in the vastness of the cosmos. Nothing. (Well that is if you ignore all those stars).
All this despite the lovely, considerate ("health and safety") lighting the neighbouring village hall provides for their car park (and the local few cubic miles of sky). I have spoken to them about this, but they are in no hurry to change or reposition the lights. What a situation for an astronomical society... when you can't control your local light pollution.
All this despite the lovely, considerate ("health and safety") lighting the neighbouring village hall provides for their car park (and the local few cubic miles of sky). I have spoken to them about this, but they are in no hurry to change or reposition the lights. What a situation for an astronomical society... when you can't control your local light pollution.
Wednesday, 26 October 2011
Our society's new "star camp" venture
Here's Cygnus the Swan and Delphinus the Dolphin setting over trees at my society's new star camp site. Unfortunately, the night I choose to camp out with my telescope was the mistiest night of the year. Still, this scene looked rather lovely. This is a composite of 13 images of the constellations setting in the west, in the wee hours.
Tuesday, 25 October 2011
Embedded deep in the centre of the milky way is a stunning stellar asterism around the star ζ (zeta) Scorpii. Here I show the area in four levels of magnification taken with various optical pieces of equiment, while in La Palma. The wide view was produced by continuously taking 15 second pics on a little tripod, through a 50mm f/1.4 lens. The next level was 2 minute exposures through a telephoto lens on a low zoom atop an Astrotrak platform that wasn't quite aligned, at f/3. The following image was produced from 4 x 5-minute exposures at nearly full zoom that were possible once the Astrotrak had been aligned. The last picture is a mosaic of two 5 minute pictures taken through a guided 4-inch vixen refractor, using an astronomy-modified Canon 350D.
Monday, 17 October 2011
Space ripples.
Here's take 2 on an object I virtually started my blog with. That's 200 posts ago. Yes, it's yet another big swirly nebulous thing! 6 x 2 minute exposures on the 20" newtonian at f/3 (focal reduced) with my astro modified Canon 1000D. Then I went back on a moonlit night, reassembled my focal reducer and got some flat fields. They made all the difference, even just as jpegs, which are pre-processed. Andy, you seriously have to try that man, it's a gas. You can see where I had to do my detrailing trick on the stars at the right hand side. This picture demonstrates the reason why you shouldn't expose for over a minute on a flipping "alt-az" when it's pointing high. Field rotation is the reason I focal reduce an already f/5 scope. I have over blurred the fainter regions in processing so I can enhance the contrast just a little bit more. The pretty object is a supernova remnant and what you are seeing is shock fronts as ripples expanding from what I guess is now a black hole or an inactive neutron star, but no one has been able to see much, just a little bit of hot metallic plasma. It all happened just a few thousand years ago, plus the 1500 years or so that it took the light to reach us.
Wednesday, 5 October 2011
By Jove!
We stayed up on a crisp, clear night until the dazzling Jupiter rose high in the South at our observatory. We put our cameras on the 20" scope and spent ages tweaking focus and getting sequences of shots. I settled on covering the scope with an 8" mask, positioned at the lower end of the aperture to minimse the seeing distortions. This helps by matching the aperture scale with that of the atmospheric turbulent cells. We got a dimmer, but much sharper picture. I grabbed forty 1/50" exposures using a 2x barlow on this set up, to give an overall focal length of 4.8m at 0.2m aperture = f/24. I used large jpeg format on the Canon EOS 1000D(mod). I stacked 39 in Registax and upon wavelet sharpening, it revealed this wonderful detail. I had some trouble using Registax that wasted many hours, but I got there. Still, I didn't manage to select only the best quality pictures, so all got stacked. The highlight of this night was peering into the eyepiece and seeing the sharpness of the storms, belts, the light pink GRS, and best of all... the moons appeared as sharp disks! I was blown away!
Friday, 30 September 2011
The Jones Nebula
This is Jones 1. I got a good shot of it in my early days at Breckland Astro Soc. And again, on wednesday night this wipsy planetary nebula was picked up with some 30 second shots on the Atik 383L. I combined about 15 luminance (70% weighting) with 4 of each colour. The Red images showed virtually nothing. A very blue-green large puff of gas, with the central star the bluish one of the little asterism that has gathered there. The star is a white dwarf which is pumping out ultraviolet radiation that is being somehow absorbed by oxygen ions (with two electrons missing), and re-emitted at that turquoise wavelength of around 500nm that our eyes are particularly good at seeing at night. This thing is visible in a large scope, but only just. It lives directly above the square of Pegasus (well it does in my mind anyway).
Wednesday, 28 September 2011
Bubble, (Hubble?), Toil and Trouble.
Well it was no toil or trouble last night to attach my modified DSLR to the 20" scope and collect some pretty pictures of the Bubble Nebula NGC 76-somethingorother (I'm getting lazy). - Sorry, NGC 7635. I want to learn all my NGCs but there are too many - some don't even exist! And this picture is certainly nothing like a Hubble view, not even a Hubble palette (which I don't find aesthetically very pleasing). However, it's my best shot of this thing yet, I have posted this object before. I thought I'd go back to DSLRing, for convenience, rather than persevering with the monochrome CCD. It was just 26 pictures and 13 darks at 30 seconds each at ISO 1600, and I was enjoying a cup of coffee during the continuous exposures, of which I rejected none. Nice when everything works!
Sunday, 18 September 2011
The cold dark world Nereid.
I blew up the contrast on my picture comprising 18 1-minute exposures on the Neptune area, taken on Sep 4-5, and aligned it with an adjusted Deep Sky Survey image of the same area of sky(inset). I flicked between them and saw a dot where Nereid was. Starry night pro was a bit wrong, but Redshift had Nereid in the correct place. This is a tiny moon!!! 18.7 mag. My photometric measurements showed it to be 18.9 mag. The main moon Triton (hardly visible in most telescopes) is bright and merged into the glare of Neptune in this picture.
Wednesday, 7 September 2011
200!
Congratulations, me! This is post number 200! It just happens to be Barnard's galaxy. I thought we would be rid of opportunities to photograph things in Sagittarius before long, so, on an extremely rare evening when it was actually clear almost to the horizon, I took the opportunity to capture some faint, weird stuff with the Atik CCD camera. This weird stuff is a local, irregular dwarf galaxy, but if you look towards the bottom of the picture you can see three blobs of nebulosity, the one on the left looking like a ring. I haven't researched this object much, I just relish its obscurity.
Tuesday, 6 September 2011
A long time ago, in a galaxy...
21 million years ago to be exact. Here's the thing everyone's raving about at the moment. It's when the light from this big bang, in a nearISH galaxy reached Earth. By ISH I mean 1,300,000,000,000 times further away than the sun. I think I spotted it in binoculars. Image from Sep 2 22:00UT. It's rather bright as these things go. It started when a white dwarf star sucks mass of its partner, which causes an instability. That leads to violent nuclear reactions, which cause an incredible shockwave that we are seeing now.
Friday, 26 August 2011
ρ Ophiuchi
This area looks like a child's painting. It's amazing how something so colourful formed out there on the border of Scorpius and Ophiuchus. It's just 4 x 4 minute pictures through a telephoto lens, looking at an area about the size of the palm of your hand at arm's length. Everything just happened to be in this one place: reflection nebula (top), dark nebula (left), hydrogen emission (right), a red giant (bottom), globular clusters, milky way. Wow! The red giant sitting at the bottom of the picture is Antares and it truly is a huge star. It is 8 HUNDRED times wider than our sun, and about 10 THOUSAND times brighter. It lights up the whole cloud with an orange glow! It is far wider than Mars's orbit. Next to it from our perspective is the globular cluster M4, which of course lies much further away. Personally I like how the star at the right (sigma Scorpii) is blue, yet is surrounded by gas that is fluorescing red. A fainter red emission cloud can be found off the bottom (south) edge of the picture. The maddest thing about this object is that it is REAL. This is a real place, just as real as the chair you are (probably) sitting on as you are reading this. Sure, it is a few hundred light years away and we happen to have a particularly nice line of sight of it, but it consitutes a lot more 'stuff' to the universe than little planet Earth.
Monday, 8 August 2011
Celestial Mire
Thursday, 4 August 2011
The spine of the night
The Galaxy's spine is defined by tenuous but vast dust clouds, shadowing the myriad of stars beyond them. From this angle, it appears to be resting, asleep, with its back toward us. The North America nebula is over at the left in the constellation Cygnus the swan. Moving right, you pass above Aquila the eagle and Sagittarius the archer, and arrive at Scorpius, which is where the horizon intervenes. Taken with a 180º fish eye lens, a few minutes of exposure at f/2.8 revealed this panoramic view between the treetop and the mountain.
Friday, 29 July 2011
Moon upon a stick (nearly)
Well, a fence. I love the way the moon has just rested itself ontop of it. Unfortunately, I couldn't get anything in focus because the moon was about 20 MILLION times further away than the fence. I managed to make it into the shot, just, but I was severely out of focus. Not the best shot, but it represents a significant moment on the last day of my hol, on July 2 2011, when the new moon returned, signalling the end of another astronomy month. I wonder, did anyone get the second, deeper, hidden pun in the last post?
Thursday, 21 July 2011
Bug
Here's a shining example (ha, ha) of a planetary nebula. This is the Bug nebula (NGC6302). Its unusual shape reveals a ring of dark material around its middle, containing such delights as calcium carbonate (chalk to you and I). Chalk? Surely, that can only be formed from dead sea creatures' skeletons compressed in to rock and up thrust to form, say, the white cliffs of Dover? (I hear you ask). Well no, here it is, out in the reaches of space, in the constellation Scorpius. This is a fine southern object, captured with the ST8300 on the Relay Cassegrain at La Palma. Looks like a scuttling squirrel to me. A red squirrel! I had trouble bringing the dark and light areas out on this, but found that Digital Development in Maxim did a fine job. Then I had to find a clever way of taking out all the red green and blue hot pixels. Interesting little object, whatever creature it resembles.
Friday, 15 July 2011
More pretty stuff
Like a glowing flower in space, the Trifid nebula is suspended in the celestial firmament above the Lagoon nebula in the constellation of Sagittarius the archer. Visually, the colours cannot be seen, and in fact look oddly reversed from that on photographs. This is a wonderful photographic target, that rises high in the sky from mid to tropical latitudes, southwards. The combination of colours arises from general 'dust' that scatters the light, reflecting and enhancing the blue colour of hot stars that light it up, and hydrogen that fluoresces at red and blue wavelengths. Much of the hydrogen light is resonant fluoresent, i.e. glowing back at the extreme ultra-violet wavelengths of 121.6nm and beyond (compared with our visible range 430-630nm). However, this harsh, invisible-coloured light is only detectable above the atmosphere. In this light, our galactic neighbourhood would look vibrant. We just get to see the little red portion (656.3nm) on our photos and, visibly only the tiny fraction that is blue(486.1nm) is detectable to our eyes at night. The picture was taken on a Vixen 4" refractor (with some serious chromatic aberration that I've already reduced) and was just 1 5-minute exposure. Compressed quite badly, or as I would say, Jpegged to high heaven!
Thursday, 14 July 2011
M83
This is a massive, swirling whirlpool that peeks above our southern hedges for a couple of hours on spring nights. However, head south and it rises right up into the starry heavens! So people like me can snap it like over enthusiastic nerds. The southern pinwheel galaxy, or M83, is part of a local little group, and it is associated with Centaurus A. It is about 15 million light years away. All those little red flecks in it are vast nebulae of fluorescing hydrogen. This pic was taken with an ST-8 at prime focus of the 16 inch relay cassegrain at f/6. Four luminance frames of 5 mins each, 4 luminance darks, plus 1 binned red, green and blue. Unfortunately, the dark that accompanied the colour images had some ghost stars on it, hence the inverse colours I couldn't quite get rid of. I have tidied up this image a lot as it is. It's been crudely processed for web use but still looks great! For example the core is totally whited out - sorry. Compare it to my previous M83 to see the sheer improvement.
omega centauri
Wednesday, 13 July 2011
omega centauri
Look at this! I could see it with my naked eye. It was named as a star in Centaurus because it's so bright, but it isn't a star. It's hundreds of thousands of them. It's much too far south to see from Britain. We got a great view of this on the first night through the 16 inch relay-cassegrain scope at astropalma. It was elliptical, which means it must be spinning. But I was impressed enough with seeing it outside through binoculars and then finding it by eye. It's a huge and quite close globular cluster happily orbiting away, floating gently around the middle of our galaxy. I got some close ups too. The little blob above it is amazing too. It is the radio galaxy Centaurus A. I didn't know it was so bright. It looks like an inverted galaxy because it has a bright fuzzy circular background and a dark dusty middle. Obviously you can't see it in this picture, but again I have some close ups, so watch this ... space.
Sunday, 10 July 2011
Amazing place, amazing lens
I thought I'd do another little advertisment for my equipment and holiday. The lens used in this 30 second shot covers from Scorpius to Polaris! This view was from the plinth at AstroPalma looking across to the astrotrak and remote dome. I hired the f/2.8 Sigma 4.5mm 180 degree fish eye from lenses for hire, and it JUST (or maybe not?) focused with my modified Canon EOS1000D. The trouble with modifying a camera is that the removal of glass makes a tiny difference to the focus. Fortunately most lenses focus a bit beyond infinity, but with this one the tiny TINY focal length made the focus point crucial and it only just made it to focus with the ring at full turn. Phew! It is impossible to use live view at night with this lens - no star is bright enough and Jupiter wasn't risen from behind the mountain. I had to find a street light in this dark sky location. Fancy that, wanting light pollution? Mad.
Labels:
Astropalma.,
Canon EOS 1000D,
fish eye.,
gorilla pod,
Gorillapod,
Sigma
Wednesday, 6 July 2011
Astronomy is such hard work
Here, the modified Canon 1000D sits atop the AstroTrak, its sensor receiving aesthetically arranged photons, which hailed from a distant nebula, channeled sweetly through a sigma telephoto lens. The only criticism here is also the thing that makes this photo look good - the damned red light! I lost my bit of tape that goes over it. The 350D's light only came on during data transfer, why did Canon decide to switch it on during the exposure?
Tuesday, 5 July 2011
Backlog
I have had an amazing trip with 100% clear skies. Hence I was spending my time outdoors rather than blogging. However, now I must go to work and process my pics. I have a selection I've done so far of 'exotic' southern milky way objects. Mm-mm-mm! No that's not millimetres, but if you want to know the mm focal length of the instrument used in this pic - it is only 300! Using a starlight express SBIG ST-8 on this little scope gave us this wonderful wide field of Barnard 72, the snake nebula. I have blogged this object before, but never in this much depth or area. This is a single shot of 5 min. I think the scope is around f/6. At the bottom left just off the edge is the star 44 Ophiuchi, which can be used to find these objects. There is a dark kidney bean or cashew nut shaped nebula that is sitting on a star (B74) , going up and right, you come to B70, B69 and then the super dark B68. Over to the left of this field of view is a wonderful big straight dust lane sticking out of the milky way that I could see with my bare eyes!
Friday, 1 July 2011
Bye bye UK sky
I am currently enjoying the stunning delights of La Palma skies at a little observatory on the west of the island. The faintest stars I could see were 6.0 magnitude against the milky way and the atmospheric transparency is great. They also have a light pollution law here. Here is a picture I processed of the Teapot asterism in the direction of the centre of our Galaxy. I hired a 50mm f/1.4 lens, which I put on my modified Canon 1000D and stopped to f/1.6, and without any tracking whatsoever I got 16 pics of length 15 seconds atop a little gorilla-pod. Sagittarius is so high here it is easy to see the lagoon nebula (top) without binoculars, among many other objects: omega centauri, the dust lanes across Ophiuchus are obvious and 'strange' constellations like Telescopium. You can't beat coming this far south for views of the milky way.
Friday, 17 June 2011
Spirit
The end of the Martian Rover, Spirit.
http://roopeshsingh.blogspot.com/2011/05/heartfelt-goodbye-to-spirited-mars.html
http://roopeshsingh.blogspot.com/2011/05/heartfelt-goodbye-to-spirited-mars.html
Dusty Streak
I found this unearthly, linear wisp when exploring the outer space behind the sunflower galaxy in Canes Venatici. It’s called NGC 5023, but I had no idea how straight and thin it was, nor how diffuse or hidden its nucleus is. I think some creator was designing something in the sky for us to see. He/she/it drew a line too long and realised he/she/it had made a mistake and rubbed it out. Well it turned out that he/she/it had one of those rubbers that don’t work very well so it left this smudge behind. Or… it could be the creator’s cosmic firework, which is the size of a galaxy, burning up in a black, intergalactic ocean.
Friday, 10 June 2011
Bang
I can't believe that. My lovely words just all disappeared! It was my best writing ever! I literally highlighted the text then it went white, paused and said "Autosaving draft". The draft was blank. Thanks blogger, I hate you. I hate you. I suppose I better write all that again.
Well...crash, bang, wallop. First it brightened, then fainter, brighter again. What's going on? Well this is a Type II b supernova. It's the little spot on the left of the galaxy. Like any other dying star, its outer layers of hydrogen began to be driven away out into space. Although deep down in the core was a different story. The atoms were frantically and desperately fusing into heavier and heavier elements. Silicon was becoming nickel, which became iron. That's as far as fusion can go. But before much of this was made the helium core alone had reached a point where it's own weight was too much for its atoms. Suddenly, the atoms were crushed and started to mercilessly fall inward to the core. On their way the protons, neutrons and electrons (remember your high school chemistry!) all became neutrons, briefly forming heavy elements like iodine, gold & lead. This was no ordinary ride, the particles were accelerated to thousands of kilometers per second! As the neutrons all neared the centre, they bunched up against one another and made a solid neutron ball. Hitting this brick wall at 1000s of km per second, created a huge, HUGE shockwave that rebounded all the infalling matter back outwards, blasting space with 200 million sunpower of energy. What I saw through my little eyepiece was a point of light. From earth, the view was masked by the outer hydrogen atmosphere. But now this atmosphere has been rendered transparent the full rage of the supernova's energy has come through, causing this second brightening. All of this was happening 23 million light years away, which means it all happened 23 million years ago. Awesome.
Sunday, 5 June 2011
The Sun
Finally I had all the things come together at the right time (well nearly), the right place, the right weather, etc. to use our Solarscope. The Coronado Solar Max was put on an EQ mount on the observatory annexe's flat roof on Friday evening and I set up as the sun was sinking behind some cirrus clouds. Having achieved such a good North West horizon me and the tripod were very visible and got a toot from a passing car. I grabbed a sequence of shots after many test shots and adjustments (position, ISO, focus, exposure), just as the sun emerged from the bottom of the cloud at 19:30 UT (20:30 BST). After initially thinking that even they were overexposed, I found that it was just the custom white balance settings had made it look that way, and the raw files were fine. However, there is still a gradient across the disk of the sun. I think its because we have such a narrow-band H-alpha filter. The granulation and structure on the sun is AMAZING! And you may also notice that it's flattened by atmospheric refraction. I know there are better pics out there but I'm well impressed - this is my first serious attempt.
Processingwise, I input the 11 x 0.04s Canon(modded) raw 10Mpixel files in Registax and they stacked very slowly - it's the only program that worked. I sharpened up the monochome output. I added a yellow colourize, rotated and flipped to correct for the diagonal mirror. Then I masked out the bright disk and turned the atmosphere a beautiful shade of hydrogen red!
Wednesday, 1 June 2011
Perspective
The moon (la lune/luna, der Mond, y lleuad, etc.) is seen in such different ways. It's a matter of perspective. I don't mean technically, like lines shrinking away to vanishing points, but a human sense of a different perception. I was walking through a beautiful rural/suburban landscape on a Sunday afternoon (April 10) and I looked up at a tree to see the moon behind it. I had my 400mm telephoto lens with me so I took a pic and to my annoyance the moon was not in focus with the tree. So I carefully focused on each one and spliced the pics together. Typical photography... it's all about seemlessly cheating, but as I was playing around, I had the idea of upping the contrast to the point where it posterized the colours. This made the faint wispy cirrus stand out, and a couple of flecks of dust unfortunately, but I like them. Unfortunately the extra contrast meant I had to be extremely seemless in joining the pics, so after a little tweak here and there I was happy with this. A different perspective on the moon. There are lots of things you could say about this. There's a lot of texture. A round moon caught between spidery, spindly branches and a soft, sketchy cirrus. Hmm I'll shut up now. I just like it.
Monday, 30 May 2011
Supernova
This is SN2011at in PGC26905 Hydra. I would like to get into doing something useful so I thought I’d make a start by finding what supernovae were out there. I found this on AAVSO.org (American Association of Variable Star Observers). Variable stars are not really my interest, but making an accurate measurement of the brightness (photometry) would give me some satisfaction, and if it were to become easy or routine to measure, it might just become rewarding enough to contribute to ‘citizen science’. I have authored a few papers so am aware of what is required, and it is usually a lot of work and stress being accurate enough. However, with the equipment here in front of me it seems a bit of a shame to use it on frivolous fancy pictures alone (as lovely as they are!). Now we have an Atik, we just need a V filter to speed up the process. The trouble with photometry with a DSLR is the green channel data only approximates a V filter and needs to be corrected using the colour (Blue-Visible) value as well as the atmospheric extinction and field flatness.
I got an estimate of 14.90mag at 2320UT (06/04/2011) but that could have been out by + or – 0.20mag and I didn’t have a good selection of reference star data (error based on differences between reference stars and measured values). If B-V for the supernova is 0 then there is a +0.13 correction, so it is 15.03 mag, if B-V=0.7 then correction is 0. The image was also so blurred that the supernova light mixed with the galaxy and some nearby stars. So there could be another + correction. Still … pretty good for a start, and for a faint PGC galaxy low down in Southern Hydra.
I got an estimate of 14.90mag at 2320UT (06/04/2011) but that could have been out by + or – 0.20mag and I didn’t have a good selection of reference star data (error based on differences between reference stars and measured values). If B-V for the supernova is 0 then there is a +0.13 correction, so it is 15.03 mag, if B-V=0.7 then correction is 0. The image was also so blurred that the supernova light mixed with the galaxy and some nearby stars. So there could be another + correction. Still … pretty good for a start, and for a faint PGC galaxy low down in Southern Hydra.
Sunday, 29 May 2011
29P/Schwassmann-Wachmann (1) 2345-2351UT 06-04-2011
This faint comet was swimming through Sextans near Southern Leo and it plunges back through the border into Leo in late June 2011. Normally its feeble luminosity would hover around 13th magnitude, but it had had a little outburst that peaked around the time of my 6x1 minute photos (April 6 2011), putting it at perhaps 12th mag. As is usual with comets to me, they look much fainter. As well as dust in the comet's tail, there is some dust obviously on my camera's sensor.
The Headphones Nebula
This secretive little critter is lurking in the unlikely constellation of Lynx (the Lynx in case you didn’t guess). For some reason, you don’t normally find planetary nebulae there. It is called Jones-Emberson 1 (PK 164+31.1). The same Mrs Jones, I believe, that discovered Jones 1 in Pegasus. It looks about as faint as Jones 1, although is listed as brighter. As all astro-imagers say “it needs more exposure”; I only got 10 minutes of good enough quality images. Well, yes, it is a noisy (grainy) image, but it is also one of those very pleasing rare and unusual objects. The nebula looks a little bit ‘on the skew’ but is roughly symmetrical, making it not really look like its moniker above. I had to restack this using the super pixel mode on Deep Sky Stacker to get it to pick 10 1 minute frames, rather than the original 8. I’m a big fan of the super pixel mode – it combines the 2x2 colour matrix into one nice coloured pixel, and means I am not over sampling the image as much. Plus it speeds things up by a factor of 4.
M61
We got an Atik CCD! Woohoo! It’s a 383+, with an 8.3 megapixel 22mm diagonal Kodak chip. Here is a picture of M61, luminance. Stacked in Maxim from 30 x 1 min pics binned 3x3 (9 pixels read out as 1 for extra sensitivity) with the camera at -10deg C. I’ve processed it so you can see all those extra faint outer spiral arms and galaxies around it. I was struggling to combine the 2 x 1 minute Red Green and Blue exposures with the Luminance – the result is below, detrailed a little. Now we’re just fighting against tracking errors and light pollution!
** NEBULA CAUGHT HIDING IN CLUSTER **
The star Sirius twinkles on a late winter’s evening. Around it the stars of the greater dog, Canis Major lie. If you imagine a line between the dogs front leg and Sirius, extend it back through Sirius 2 – 3 lengths you will come to the star clusters M46 and M47. This is a close up on the North of M46, with all the brighter stars on the image being cluster members. As you can see there is a planetary nebula (NGC 2438) lying in the same direction as this cluster, which I have brought out in the processing. The nebula is probably closer to us than the cluster, and thus is not really hiding within it. It’s a nice thing to view but sadly we’ll have to wait until late in the year before this curious alignment is in our skies again. I moved the blue down and red up to correct for the atmospheric refraction messing up my pictures of low objects!
Pastel shades of wispy gas
I stuck an 8 inch mask on the 20 inch to cut down the blurring effects of seeing, not realising that by doing a long exposure would reintroduce the blur. Nevertheless, because I was pointing the scope at such a beautiful bright region of spacetime, I captured a pretty pastel picture of these wisps of gas without diffraction spikes. There is a little tuft on the edge of each star, presumably caused by the central mirror edge protruding slightly into the 8 inch mask. I may have saturated the trapezium at the centre, but the nebula centres have come out deliciously mottled and shaded. Especially, see the star at centre bottom with a deep shadow next to it.
Thursday, 28 April 2011
Sombrero!
The billions of stars that make this wonderful smooth shape, which appears nearly edge on from our Galaxy, lie 29 million light years away, in the south of the constellation of Virgo. This vast stellar city is nicknamed the Sombrero galaxy for obvious reasons. Officially known as M104, you can see the bright nucleus, and sharp, symmetrical dust lane around the edge. There are also 1 or 2 background galaxies visible. M104 has been imaged in infrared light that penetrates the galaxy to show the dust lane going all the way around. It's an incredibly aesthetically pleasing object that 'floats' in the sky like saturn with its ring. It lies quite a way outside (south) of the main Virgo galaxy cluster, but is quite bright due to that nucleus. It is a little smaller than you may expect, and the dust lane can be seen with a moderate telescope from the UK, low in the southern sky in spring. This picture was composed from just 7 x 1-minute exposures on the 20-inch BAS scope at f/3 (along with some daylight flat fields that didn't work). It just looks beautiful to me.
Tuesday, 19 April 2011
Jellyfish
Now I’ve got my modified camera – look at all the red stuff it reveals. This is the jellyfish nebula that I blogged before. I can now see all the red stuff - Hydrogen galore! – it’s like taking off a pair of sunglasses. I mosaiced 2 pics here. Both were guided on Propus, which is responsible for the shard of light you can see just off the bottom. The jellyfish gives a lovely impression of the nebula floating in the vast sea of the heavens.
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