Monday 25 September 2017

The Spring Gegenschein

We host a Star Party in East England at a Dark Sky Discovery Site close to RSPB Minsmere. The sky has reached an SQM level of 21.75 magnitudes per square arcsecond there, and it is dark enough to see the Zodiacal light after sunset in spring. There still is some light pollution, but much less than most places and it is really a very impressive site. What's more the company is great - it is a gathering of like-minded astronomers from semi-local societies. After having seen the Zodiacal light there in 2016, and again (but slightly less clearly) in 2017, I thought I'd have a go at taking lots of exposure on the patch of sky where the 'counterglow' or 'gegenschein' lies. The Zodiacal light is a line of scattered solar light, that follows the ecliptic plane (in which we're embedded) - so in spring you can see it passing by the Pleiades. There is also another scattering phenomenon caused by the dust that lies in this plane. It is called 'backscatter'. I was trying to see it with my naked eye and couldn't be sure, but there was always a hint of a patch of light in Virgo, near Jupiter. There was still too much background sky light to be sure, caused by distant light pollution scattering off atmospheric moisture droplets and thin cirrus clouds. After gathering about an hour's worth of snaps on both nights I was there, the cirrus closed in on the second night (which was clearer, darker & drier) and I thought I'd have a good chance of processing the data to show it. Sure enough after a straight gradient removal of light pollution, there was a blob at the expected position along the ecliptic. It didn't quite correspond to the position and shape I (thought I) saw it with my eyes, but it was very close and ~ 80% overlapping. It could be, the stars or Jupiter interfered with my visual perception. The standard kit lens 18-55mm did really well here at f/3.5 and 18mm, with 5 minute sub-exposures. 18 in total were useable, or 90 minutes. Here is the result. You can see the processed-out cloud at the bottom right, due to Virgo sinking. Try to pick out the constellations!

Sunday 24 September 2017

Early Autumn Skies

In Early Autumn, you can catch a nice glimpse of the Milky Way in dark skies, rising from the SSW, where we look into the centre of the galaxy. Unfortunately it is very low down so we look through a lot of interfering atmosphere and consequently light pollution (produced by either ignorant, paranoid, or uncaring folk that install inappropriate outdoor lights). Despite this impedance, the power of long exposures, stacking and a lens that runs at f/2 (stopped to f/2.2 in an attempt to cut down abberrations) can be used to produce a good image. Cloud, twilight and mist were threatening to spoil my attempt but the moon was out of the way at last! There is so little time for astronomers to get good viewing conditions we have to seize opportunities like this. I have stacked 7 x 1 minute images taken at ISO 800 tracked with an RA motor, with my modified Canon 1000D, with a 100mm prime f/2 lens from a quiet, dark site south of Norwich. The region is North Sagittarius/Scutum and it contains M24 - the sagittarius star cloud, M17 the swan nebula, M16 the eagle nebula, and numerous other nebulae and clusters.

Another shot at the I.S.S.

Apologies for being away for a year and a half! The gaps between my blog posts have been growing wider and wider. In the meantime I've been running an astronomy society. I thought my first post back would be to see if this year's attempt at catching the ISS is any better than the Feb 2016 one. Same tech, ZWO ASI 130MC camera at f/10 on 8" SCT manually driven. It is very hard to follow the thing at the best of times, but the camera also has the problem of a rolling shutter, which makes it really unsuitable to capturing fast moving objects. This is especially true for stacking purposes. I therefore corrected the best 10 shots, by de-skewing them, and making sure they were taken within a few seconds of each other. July 27th 2017 pass over UK.

Saturday 13 February 2016

Attempts at imaging an object at 17100mph

Here are my ISS images through my 8" SCT. The first was taken on January 17th at about 5:30 am. It was spooky watching for it as the shadowed station appeared on live view on the Heaven's above app on my phone. It appeared exactly on cue and I grabbed my telescope ready to move it by hand. I started recording and looked down the finder scope. I tried my best to position the scope so the bright spot exactly crossed the crosshairs. On looking at the video, however the shutter speed had been so fast (1/1500") it had skewed the image. For the second attempt, on the evening of February the 10th, I used 3ms (1/300"), and perhaps this was too slow as there was some blurring. It is a learning process, so next time I'll aim half way between and set the gain a little higher. The solar panels were pointing toward the sun and so were lit only faintly by the reflected light glancing off the earth, but they look brownish in the second image. The illumination angle was pointed out to me by Mike H from our society.

Friday 9 October 2015

Obligatory moon shot!

After a warm and cosy hour's sleep, I forced myself to get out of bed to catch this rare occurrence. I think UK has been a bit unlucky with lunar eclipses recently. America seems to have got them all. The clouds cleared for me, but friends just down the road had a different story. I composited 6 shots through my 8" SCT to get this one, plus co-added and blended in a non-saturated moon. I tweaked the saturation and sharpened a little. Beautiful sharp stars with this technique!

Thursday 8 October 2015

Kielder Water

We went on a drive up the spine of the UK to Kielder Water - and took advantage of the dark sky park status. These are some pictures we took on Monday night. It was pretty dark up there, but the cloud was rolling in. We stopped at a view point off the South side and got some simple long exposures of different lengths and focal lengths on the Canon 1000D with just a tripod as the moon was setting. I've processed a little in photoshop/paintshop. Spot the 'moon-dog'. The milky way shots didn't come out well as the lens misted up very quickly! The observatory at the top of the hill at the far end was a very welcoming and fantastic little place. It's an innovative design - almost like a jetty with two fairly roomy observatory domes along it's deck.

Sunday 23 August 2015

Scouting around for good astronomy sites

Hello. I've just moved and I thought I'd do a spot of astro reconnaisance of my new sector. After checking out Google Maps/Earth I headed out from the city and got rather lost trying to find my original target location. I ended up somewhere very rural and dark, but it was such a beautiful warm night - 20ºC at 11pm. I was in a T-shirt setting up my 8 inch SCT and Canon 1000D on top. I had found a lovely dry field with easy access off the road and a very open south, and well, all horizons. There was just a small hedge to the north. I encountered one passer by in the 2 hours I was out there. I managed several 2 minute tracked wide field exposures from atop my telescope. I didn't realise the field was full of hay bales until I took the first exposure! Here's the result - I tried to remove the gradients and enhance the local contrast to bring out the structure in the Milky Way, but there was some ludicrous light-pollution even here (somewhere N of Saxlingham Green, Norfolk). A nice night. Incidentally we had 28ºC, while the rest of the UK had persistent rain and about 19ºC. However, we got rain today - healthy garden I guess.

Saturday 11 July 2015

The Lagoon Nebula

This nebula, which first appeared to humanity in 1654, by Italian astronomer Hodierna, was catalogued by Charles Messier as his eighth entry. It appeared as an interesting fuzzy smudge, behind a sparkling little star cluster and 4 stars in a line. This is a modern-day picture of it using the following equipment: an iOptron equatorial mount, a Celestron 9.25 inch Schmidt-Cassegrain, a f/10 to f/6.3 focal reducer, an Atik 383L+ CCD camera cooled to -20ºC (which had the usual temporary icing problems), a 1¼" filter wheel with Luminance Red Green and Blue filters. There was no guider used with this, so we limited the exposure length to 30 seconds, which could have gone higher but the wind occasionally would spoil a frame by shaking the telescope. The dew shield was removed, due to the wind. The other operation problem in taking this was the observatory wall was located about 15 feet to the south of the telescope, and at 8 foot high, meant the lagoon nebula was shortly about to 'hit the wall'. Luckily colleagues stayed on until midnight enabling me to acquire at least 12 images through each filter. Given the altitude of the subject (about 10º above the SSE horizon), it's not a bad image. Processing this was difficult, due to there not being any time to take any calibration frames. This keeps the noise down but gives horrendous vignetting to remove, which is especially hard when nebula fills the frame. The 'hot pixels' that pop up, were removed using a clever stacking technique, called sigma clipping, and there was no dust on the sensor to spoil the image.

Sunday 14 June 2015

Saturn heading South

While the rings are nice and open like they were in 2003, this time round, Saturn has moved South, Causing it to glide through the murky, churning atmosphere from UK. There are several ways to get better pictures of Saturn: wait until better seeing and persist with the best equipment possible, wait 8 or so years, move to Australia, set up a telescope on board a plane, install a sodium laser at the observatory and use adaptive optics on the primary mirror, be Christopher Go, or give up and use Hubble's pictures.

Wednesday 27 May 2015

Norwich by Night 2015

With a bit of stacking and processing, Norwich is beginning to look like some sort of dark rural location. I'm lucky to live on a street where the lights are switched off at 1am BST. The sky was quite light really but the sky has been stacked and processed separately from the houses. "Norwich by Night 2015 has been spoiled by some cloud streaming in and the dust bunny to the right of the centre, but for me it's quite amazing to see the milky way from a city. Only the Scutum-Aquila cloud (upper left)was visible to the naked eye through the window, but the rest of the detail was brought out with contrast enhancing. I particularly like how I caught a faint reflection of my face peering over the roof corner at the centre, just to the right of the Lagoon Nebula.

A librated, saturated moon

The "top right" bit of the moon on April 26th with the colour saturation enhanced by 500%. Maximum libration point was just beyond the 'sea' near the top centre, which means we can see slightly round the edge of the usual face of the moon. The 'sea' is Mare Humboldtianum. The moon seems to be muddy brown and electric blue, when you turn the colour up.

Fleeting Mercury

Mercury above the rooftops at 21:56 BST 13th May. Snapped by poking my telephoto lens out of my bathroom window. ISO1600 f/5 1/15". It's always very low in the twilight, following the sun down, and it's only visible for brief windows of time, if it's clear. An elusive, vespertine planet! The camera lens's resolution isn't enough to resolve the shape of the planet but I've included a 5x inset.

A conjunction and strange things flying above my head

The night of April 11 was a nice little trip to the observatory, watching Venus and the Pleiades setting over the dome. I settled on this picture, which makes the dome loom large like St Pauls Cathedral, rather than the close up on the conjunction, which showed the gibbous phase of Venus. I also managed to spot the International Space Station beginning a flyover, so I repositioned the tripod and my head hoping to capture it flying past. Previous experience has allowed me to judge where to position myself but keeping still for 30 seconds is not easy. It's a lovely composition of cloud, space station flying through Lynx, Leo, Jupiter and Praesepe - the Beehive cluster and Pollux and Castor just above the dome.

Sunday 17 May 2015

Io and Europa's close encounter

Here's an example of where reality can get close to the simulation. I got some good seeing, and with a decent camera (a ZWO ASI) I got a decent video-capture of Jupiter's moons Io and Europa through my 8" SCT from a city backyard, as they passed by each other, at one point just overlapping. The image is in two parts, and explains itself. The angles are a bit different.

Zodiacal Light from Equinox Star Camp

Yeah! There are still parts of England that have escaped enough the scourge of light pollution, so that the zodiacal light can be photographed. I took this panorama on the equinox (March 21st 2015) from Haw Wood Farm campsite in Suffolk, near Minsmere. This is a beautiful area of the country, not too far a drive from the capital. Our astronomical society, Breckland, had a few members and guests attend a star party weekend at the campsite. I didn't however, look for the zodiacal light, I just noticed it on the photograph, once I'd stitched together this panorama. It is a series of 4 x 30 second exposures at f/3.5 on a regular Canon lens moving from South to West. The sky featured a beautiful range of objects, from left to right: Sirius, the Milky Way, Orion, the Hyades, the Pleiades, then the Crescent Moon and Venus.

Saturday 14 February 2015


Here's my attempt at Comet Lovejoy via my 8" SCT, with 2 focal reducers at f/4. The image on my DSLR is vignetted at this focal length (800mm), but rapidly builds image exposure, helping capture moving images such as this comet. It is on its close passage by Earth here, and I hope to capture it again soon. I have added a rotational gradient shot that shows the knot structure in the tail well.

The million kilometer plasma filament

I popped down the observatory to try some solar imaging with the sun low in the sky Sunday 8th Feb. After dodging clouds, I was amazed to spot this filament so clearly through the eyepiece of the solar telescope. I got 20 pictures of it with my DSLR and stacked in PIPP and Registax. The large images taxed my laptop somewhat. Here's the result, exposed for flares (red) and surface detail (green) simultaneously. What an amazing structure this is, about the width of the Earth, suspended above the surface of the sun by magnetic fields. It would wrap around Jupiter's equator with length spare, and fit between the earth and the moon and back! If it fell back on the surface a Hyder flare would erupt, but it hasn't done so in the last few days. The sun is certainly more interesting than you may think!

A winter favourite

When testing and setting up guiding and imaging with the Atik 383L camera on the C925 on the iOptron mount, you have to go for a nice bright, interesting target like the Orion Nebula. Unfortunately we need a spacer to make the guide camera the correct distance from the imaging camera, if we're using the off-axis guider prism unit. We could either guide or image, so here's the image, unguided, which isn't bad!

Monday 26 January 2015

Jupiter's triple transit

I got up at 3:30 a.m., venturing out into a frosty January night to the society's observatory. After dragging out the Celestron 9 inch Schmidt and iOptron mount, just the one hiccup occurred, caused by the video image capture software. An annoying but fairly quick restart later, all was well and I managed to get a sequence of 1.5 minute videos of Jupiter setting slowly in the West. UK wasn't the best place to image this triple transit due to Jupiter being fairly low, and in fact I haven't got the third shadow due to poor seeing. I later realised I should have got one more frame. You can see an interesting shadow exchange and Io (the moon moving across the disk) covering Callisto's (larger) shadow at the end of the animation, which runs from 0530-0621 UT, with irregular time intervals.

The image above is Jupiter on the 20-inch for comparison, the following Tuesday night. There is a slight aberration in the optical system, but the moons Europa (and its shadow) and Io are very clearly shown.

Wednesday 31 December 2014

Lovejoy emerges from the South

Our skies are graced with another comet. It is a bit difficult for us to see in the North at the moment, but will move out of the low misty southern skies in a few days. Here is my first serious attempt at getting pictures of it. I just used a 400mm lens at f/6.3 and took 40 shots of 30 second exposure on a tracking mount (Dec 29 11pm). There is a hint of a tail there and while it doesn't look much now there is more to come from this icy rock.

Saturday 15 November 2014

The Outer Gas Giants

After a successful forecast of reasonable seeing conditions in the UK (i.e. low 300 mbar geostrophic wind) I spent an evening at the observatory trying to aim a telescope so as to focus Neptune, then Uranus on a 6mm CCD chip. Despite the new mount being excellent at tracking this took some time, and it wasn't helped by the mount insisting on doing a meridian flip just before starting imaging. The 9.25 inch SCT 'scope was cooled, Neptune showed a disk in the eyepiece, and high magnification was achieved with an extended 2x barlow, to reach about 6m focal length. The only non-optimal factor was the collimation being out, which was clearly seen during a later image of Gamma Andromedae. I explored a range of objects until the corrector plate dewed up too quickly.
So I managed to capture video of: Neptune at 3x, Uranus at 4x, close-ups on Cleomedes and Aristarchus/Vallis Schröteri (which were low down and shaky), and longer exposures of the core of M31 (not shown) and NGC 7662 - the "blue snowball" planetary nebula. It was a lot of fun trying this all out freezing on a patio in a dark field, alone with the entirety of space!

Sunday 5 October 2014

Little Planet of Waveney Mountain

I went to a local hilltop near the student residences in order to try and get a 360º panorama of the sky with my Canon 18mm lens, on a moonlit night. 'Waveney Mountain' is named after the former residences, which are themselves named after a local river and 'mountain' is a little joke among folk round here. After loads of practice with Hugin, a long pause (a few months) and several attempts at stitching the pictures last night, I have finally got something I'm happy with. I had to manually choose the control points that each pair of neighbouring images shares, and there was still a problem with a black wedge appearing in the place of one of the images. Hugin is great for remapping the pictures onto a stereographic projection but doesn't quite get what looks right, so I got it to remap the problem picture and pasted it in myself in Photoshop. A quick bit of clone brush to fill in the panorama gaps that I'd inadvertently missed and here's the result. Now I can do this, I'm tempted to get a nodal ninja tripod and a wider angle lens. Astrophotography can so easily be quite a costly hobby, but this was pretty inexpensive and a great idea to test out during moonlit season.

Wednesday 3 September 2014

An re process of an old favourite

This is a quick and crude process of some stacked images of the Horsehead nebula. I took them through the 20 inch with the Canon 1000D (with the A-mod) in February 2013. I've just used the amazing Hugin software to assemble this mosaic of 4 images and tweaked it in Maxim, then applying a Digital Development Processing routine. It just looks stunning so I had to post it straightaway. The contrasting colours here make such an aesthetically rich faraway thing!

Wednesday 20 August 2014

Zubenelgenubi gets some guests!

While testing my planetary imaging demo for the talk I'm giving next month (see: ) I spotted Saturn and Mars setting in the South West. I got a snap and looked at the image and spotted a star. I then ran across the field with the tripod to get a pic of the planets above the dome and observatory. So not such a 'far away thing'. It's one of those mind-blowing distance ratios. I also caught Andy walking back to the observatory who came back telling me the star was alpha Librae - aka Zubenelgenubi, my favourite star name! So from top to bottom we have Saturn, Zubenelgenubi (alpha-2 and alpha-1 next to it) then Mars. A beautiful scene I realised when processing it to bring out the faint details, giving pleasing pastel shades on the sky. Just 1/4" second exposure at ISO 1600, I had to turn the gamma down again as blogger overdoes it!

Comet E2 Jacques

A night at the observatory and a moonless clear spell coincided! Not wanting to waste the opportunity I wheeled the society's new iOptron mount out and set up the 9.25inch Schmidt with the help of a busy crowd. I put my modified Canon on the back of it along with a f/6.3 focal reducer. Time constraints meant a full perfect drift-align wasn't possible, so I limited exposures to 30 seconds to reduce any star trails. Auto-guiding is not quite ready with this set up yet, but once we get the equipment together, beautifully long exposures will become possible! During the 20 minutes or so it took to get 22 good exposures, Comet Jacques had slid past a star and moved quite considerably! This required a special star then comet stack in Deep Sky Stacker. The result had a fair bit of star ghosting in the direction of the comet's motion and there is still a small ghost of the comet's nucleus left in the image that I couldn't remove easily. Several runs through Carboni's horizontal and vertical banding removal routine got rid of the bias pattern noise in the camera sensor, but the faint ghost trails were still a little annoying. I tilted the image until these trails were horizontal and ran another horizontal banding removal routine on the image. Then I tilted it back. Above's the result, and below with the faint parts smoothed. Not too much exposure, but am I right in thinking there's a hint of a tail to the right at about 110º CW from vertical? The green emission in the coma ('swan bands' in the spectra) comes from the molecules C2 and CN and their positive ions.

Monday 30 June 2014

Midsummer Planets

During the light nights of summer here in the UK, planets are an ideal target. Unfortunately, we are also rather far North for good planetary imaging, as they are low in the southern sky, but this didn't stop me. I used the new iOptron mount with the Schmidt Cassegrain 9.25 inch f/10. After attempting a focal length of 11.5m, I also tried cutting it back to 5m and got just as good results. With the imaging source colour webcam, I recorded video with a range of exposures of Saturn and Mars. The mount tracked well despite a quick manual align. I manually fused the long and short exposures of Saturn in Photoshop after trying out the "Merge to HDR function" with less success. So the photo includes moons (L to R) Dione, Rhea, Tethys and Enceladus - just, below the planet. Mars also had a distinct phase (88%) and is only 9.9 arc seconds tall (phase mask added). Vaguely visible are Mare Acidalium (top centre) and Mare Erythraeum (bottom) as the North pole is tilted toward us. Taken 22UT 24th June 14.

Monday 19 May 2014

Cometary Conjunction

I managed somehow to get an image out of the 20 inch scope after its drive rebuild. It has been out of action for imaging for months. The drives are still in their development stages, and I'd disassembled my focal reducer adapter for that scope. I had to image in short exposures (20s) and pick the best 30% or so. It was an ideal photo opportunity with the 3.7 magnitude guide star χ Ursae Majoris, a degree from the brightening comet 2012 K1 PANSTARRS, and its usual companion, galaxy NGC 3677. Still, this lovely pairing made a great view and photo - they just fit in the frame. χ UMa is a little off the top of the field of view (around 30' across). This comet is worth watching as it passes by φ UMa and descends into the summer twilight and may become visible in the morning sky in autumn. It has moved a little (SW) during this images exposure time.

Saturday 19 April 2014

Looking Inside the Pentagon of Auriga

The area in central Auriga featuring open clusters M36 & M38, IC 417 (around central star, phi Aurigae), IC 405 and IC410 - the flaming star nebula. About an hour's worth of 90 second exposures piggybacked on the top of my 8" through a telephoto lens with a modified Canon 1000D. Taken from Kelling Heath. There was a lot of mist and clagg in the air that night, so it's not bad! There are dark lanes and other patches of nebulosity lurking around this region of the milky way.

Wednesday 12 March 2014

Jupiter - always interesting

I "videoed" Jupiter on the 8 inch Schmidt-cassegrain at the observatory tonight (11th March 2013). I got better results with just the 2x barlow than with 2 2x barlows. I was operating at f/20-22 (focal length just over 4m) and exposures of 1/54 of a second. I captured 2500 frames in 1min40, and stacked the best 1760 of them in Registax 6. The three moons made a beautiful triangle and Callisto cast a rare shadow on to the disk - something I noticed in the eyepiece, plus the red spot was in view. What chance! The Imaging Source (non-cooled) DBK colour camera was pushed into the scope and off I went. The moons to the right were (top to bottom) Europa, Io, Callisto - and you can see it is Callisto causing the shadow. Each moon seemed to have an independent motion to each other as the conjunction developed over the course of an hour or two.

Aurora borealis!

Yeah! I caught a glimpse of the Northern Lights for the first time this solar 'season' on Thurs 27 Mar 22UT. It was not too impressive aesthetically, but lovely to see the lights again. A colourless dim glow was hovering, detached from the horizon and for a time, a shaft of light appeared in the sky just beneath Cassiopeia. The advances in Camera technology (and mine is well out of date) meant an easy capture of the wonderful colours.
Here I've done a stack of 8 x 15s images pointing N, just N of Norwich. I stacked on the ground, not the stars, so they are trailed. The green, lower glow is from atomic Oxygen, i.e. O atoms, emitting during the decay from excited singlet S state to the singlet D state, an allowed transition. The red light, also from atomic O, is only seen at higher altitudes, where the air is much thinner, this would occur at lower altitude but the excited state causing it is knocked back down by collisions with other air molecules. This excited state is the singlet D mentioned above, the 'first' or lowest energy excited state, and it releases its red light with a time constant of about 107 seconds. This means it needs to avoid getting hit for about a minute, in order for it to have a change to spit out its red light. The reason for this slow time is because the transition from singlet D to the 'ground state' (triplet P) is forbidden, as the spin has to change from singlet to triplet, something not allowed by quantum mechanics.

Sunday 9 February 2014

The Milky Way over the Bristol Channel. New processing.

I have had another go at processing the twelve 30-second (dark-subtracted jpeg) exposures that I took of the Milky Way setting over the Bristol Channel last September. I was not happy with the 8-bit look to the background subtraction and the lens-distortion. I used the beautifully complex free program hugin to correct for the barrel distortion of the lens and stack the images based on a spherical geometry. I had a long task, taking many hours to work out how to get the control points only on the stars. I eventually found a method for hugin to use to pick the control points, and it resulted in a beautifully stacked final image except it came out with a distorted perspective. So I stacked the shore images and recombined the image with the stars, and ran a background subtraction. The resulting processed image is much sharper but still with very slight trails from the individual 30 second exposures. I've reduced the scale to 0.25 here (jpeg), so the trails are barely visible. Altogether not bad for 12 minutes on a tripod perched on a windy clifftop.

Saturday 25 January 2014

There's nothing like stargazing live

It's not live as we know it, Jim. It happened 11.4 million years ago. But - that's using our human concept of time. In reality time isn't a constant thing - there's no such thing as simultaneous. As far as I'm concerned, the recent supernova in the galaxy M82 has just happened, because all of us on Earth agree that its light has reached us in the last few days. That's good enough for me. Last night I was spurred on to get my 8 inch Meade LX10 SCT out of its box and onto its tripod positioned in my urban back yard. I popped in an eyepiece, focussed and swung it round to Ursa Major. After only 2 or 3 minutes of dark adaption I had seen the supernova with my own eyes. That was awesome but very quick. A near conversation on social media meant two other astronomers (whose blog links are here) had swung their kits round to image it. Thereafter I had a go at imaging it, with limited tracking and got a few 15 second exposures at f/6.3. I left it running and later did a stack of 75. A little blurry. Tonight I have selected the best 45 images out of 100 and used PIPP software to debayer and crop them around the galaxy. A quick stack in Deep Sky Stacker gave me a smooth image, and a DDP (digital development processing) gave this result. Much better than before, but only 11 minutes worth of data on a Canon 1000D is not gonna cut the mustard these days. Still I'm pleased to see it - so here it is. The society's telescope is currently unable to be used for photography, and we've been using it for stargazing live open nights, hence the lack of blog posts.

Monday 16 December 2013

Maria Smythii et Spumans

November 13th brought a favourable libration around the eastern limb of the moon so I couldn't resist taking a few videos on the ImagingSource DBK camera through the C9. The C9 is the society's 9.25" Schmidt-Cassegrain, which is ideal due to its long focal length and having retained its collimation well from last year. I decided to not use a barlow lens as I was at f/10 with a focal length of 2.35m, and captured low noise lunar detail at first quarter with exposures of under 10 milliseconds. I processed in Registax 6 using multipoint alignment and geometry correction and mosaiced 4 sharpened frames, which I've cropped here. I filled in the gaps with a bit of quick clone brush - so don't trust the detail at the bottom. I was aiming to capture the aesthetic beauty I've experienced from viewing the sharp, grey edge of the moon. Mare Smythii and Mare Spumans show up well in this image. Unfortunately, Mare Orientale - the Eastern Sea, discovered partly
by Patrick Moore, is now officially classified as being on the western edge of the moon.

Monday 7 October 2013

A HUGE planetary nebula

The Helix Nebula, a large death shroud of a star, floats across the Southern sky in October and November and never climbs higher than about 23 degrees altitude. The width in our sky (as it is quite close) is around half the size of the moon but it is very much fainter and usually buried in the murky low atmosphere. I used the large aperture of the 20 inch telescope and the society's Atik 383L camera to capture it. I got 6 minutes through each of 5 filters: Red, Green, Blue, Ultra High Contrast, and Luminance (all white light). The scope is due a drive upgrade soon but it was working more or less satisfactorily last night on this object. There were a few jitters, but no guiding was required, now that the pointing model has been reset. This planetary nebula has thrown off another fainter wisp of gas that you can make out to the lower left. The centre is glowing mainly from the emission of doubly ionised oxygen atoms and the outer part, hydrogen atoms. It was a splendid starry night, with transparent sky right down to the horizon initially, before a little mist started to form and was wonderful to look up at the Milky Way while I waited for the camera to do its thing.