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.

Thursday, 3 October 2013

Welsh skies

I was expecting good things if clear in Wales, and I was rather disappointed by the Brecon Beacons Dark Sky park. It had a large amount of glow from the South/SouthEast, and this was viewing it from the North of the park in Hay-on-Wye. The skies were very transparent and I could see stuff well overhead but the low light pollution was pretty bad. Also, the campsite owner had put up badly directed high-pressure sodium streetlights all over a beautiful little field. Hay, despite being a small place also had a few overly large lights, which affected the whole valley's look at night. There is of course the problem of clouds in the western part of Britain, let alone rain, so the view from the valleys was mist. However, when I got to the Gower peninsula I was pleasantly surprised to see all of the main Sagittarius asterism and when I got to the cliff top the Milky Way was touching the sea! The coastal light pollution to the left and right was horrendous but all there was to the south were a few distant lights on the coast of North Devon. I got the Canon on a little tripod and snapped a sequence of 30s shots, which I stacked a bunch of. In the picture here, taken after astronomical twilight, I have replaced the horizon and subtracted the large scale background features to bring out the details.

More Wales shots

Here's the view when I returned to the tent on the cliff top at Three Cliffs Bay, The Gower, Wales (30 second shot).
A view I first got after rushing to grab my camera from the car. This shows the star Kaus Australis in Sagittarius - a rare sight from this country.
A 90 second shot (detrailed roughly in Paint Shop Pro)

View from Hay-on-Wye

Some views of the sky from the North-West valley slide in Hay-on-Wye. Looking SSW (toward the Brecon Beacons dark sky park), SSE and ESE (into England). The levels of light pollution near the horizon can be seen. The bright campsite being typical of peoples unawareness of the dark sky status. I tried driving further up into the hills where it was dark indeed, but the foliage, hills and cloud spoilt my assessment of the sky.

Wednesday, 4 September 2013

Not such a 'far away thing'

In keeping with the original theme of my blog, I have been taking some "easy" shots of scenes recently, as the 20 inch isn't tracking too well at the moment. Here is the not so 'far away' International Space Station. A mere few hundred miles. When I saw this, I dashed in to the observatory, grabbed the camera, focused to where I thought was infinity and laid it on its back to do a 20 second exposure of the overhead sky. The clouds and milky way are not too prominent due to the unusually short amount of exposure time, but with minimal processing one can instantly see the beauty of the constellations Cygnus and Lyra, and the full extent of the Summer Triangle: Deneb, Vega and Altair.

Monday, 5 August 2013

Allegorical nebulae

Havent posted for a while. I have been moving. Closer to the observatory. Yes! But I'm all back and doing proper astronomy again. I tried aiming overhead in what seemed like quite a light sky, in order to minimise the sky glow, but I encountered the damn problem of Alt-Az telescope rotation. Even on short (30 second) sub-exposures. I pointed at a particular detail of a nebula in Cepheus (see post below - mu Cephei) that resembles an elephant's trunk. Or at least is said to. Well here are 12 rather rotated exposures of it, combined to show the feature up quite well. I tracked on a star near the centre, but I think I'll not go over 75º altitude again (this was at 82º+).

Thursday, 6 June 2013


For a change, I'm adding a planetary image, obtained using the society's Celestron 9.25" f/10 Schmidt-Cassegrain Telescope. I used the society's Imaging Source DBK camera and IR block filter in a 2x barlow lens, slid back to achieve more like 3x, thus giving a focal length of about 7m at f/30. This telescope works better for planetary detail than the stopped down 20" f/4.8 Newtonian, although it had to sit outside for well over an hour to cool to reduce internal air currents, while seeing also slowly improved. I recorded about 2000 frames at 1/30" on high gain and stacked the best 40% or so using Registax 6. This was taken a little after opposition (when Earth passes between the Sun and Saturn) on 7th May, at 21:31UT.

Asteroid 1998 QE2 drifts silently by

Here's around 50 minutes of footage of the asteroid 1998 QE2 drifting by us on the evening of the 2nd of June. I recorded 10 second exposures with intervals of 30 seconds on the 20 inch telescope, as the 11th or 12th magnitude asteroid culminated in the southern sky, in the constellation of Libra. You will see the imperfections in the tracking of the stars, and the apparent rotation, as the mounting is Alt-Az (altitude-azimuth, i.e. up-down left-right). The field is about 38 arc minutes across. The asteroid is quite large, much larger than the actual QE2, so it's a good job it passed a few million miles from us. Look out for the 'flash' of a (man-made) satellite trail and a(nother man-made) geostationary satellite near the end of the sequence. The geostationary satellite appears to move but in reality the right-to-left motion is because the stars are being tracked.

Wednesday, 29 May 2013

Huge local elliptical galaxy hiding directly behind the Milky Way

The asterism Czernik 11 pictured here, lies within the myriad stars in Cassiopeia, a constellation with the Milky Way running through it. It acts as a signpost to the galaxy Maffei 1. All that's visible is a nuclear region of a nearby galaxy, appearing as a diffuse 11th magnitude glow, very difficult to find or see among so many stars. Here I stumbled across it in April, after looking at comet PANSTARRS. It is hidden directly behind the Milky Way's dust and 98.6% of its light is blocked by it. In near Infra Red it appears as a huge galaxy stretching up to 23 arc minutes and were it not in the plane of our Galaxy, we would be able to see it well in binoculars on a dark night.

Another go at M87's Back Hole Jet

Here is the central massive elliptical galaxy in the Virgo Cluster. M87 is huge and has an active nucleus (supermassive black hole) that is producing a visible jet as well as two much more distant radio lobes. The jet is detectable on fairly short exposure images, such as the 22 15-second exposures used to produce this image. The area in the photo includes two other galaxies of the Virgo cluster. I avoided using guiding, and rejected a few images with motion blur during the stacking (production of the final image).

The southern pinwheel from the UK.

This is the southern pinwheel galaxy, M83, taken from the northern latitude of 52½ºN. It was under 7º above the southeastern horizon when I got the 44 images of 30 second exposure. Using RAW mode on the modified Canon, and having gathered plenty of flats of darks has enabled me to divide out the light pollution background pretty well. A bit of gradient removal and digital processing gave me this reasonable image taken through a lot of atmosphere.

Sunday, 12 May 2013

Two spring galaxies and a supernova

This pair of galaxies are M66 and M65, which are on the left and the right respectively. They are located in the eastern part of the constellation Leo the Lion, just around the centre of the Lion's imaginary femur. In M65, there is a supernova which you can see below the nucleus of the galaxy, halfway to the edge and a little left. This apparent star is not usually there, and it was brightening in the days leading up to when I took this photograph on the evening of April 6th. I took it in the usual way, with my modified Canon 1000D on our society's 20 inch motorised Dobsonian, and stacking lots of 30 second exposures. I was careful with the calibration frames in that they were gathered during the previous twilight. I've processed the image a little more gently than usual and used a digital development algorithm to make the image look a little more like peering in a huge telescope. I'm amazed with the detailed structures I can see in these two fantastic galaxies.

Friday, 3 May 2013

Detection of Distant Aurora

I was getting aurora alerts on my phone and with activity having been raging at Kp=10 all day and evening I couldn't resist driving North of the City and going for a look just before bedtime. I set up the modified Camera on a tripod and took a few 30 second, wide angle shots. One short sequence shot at around 2300UT on May 1st, showed a noticeable change when I flicked through it. There were three red vertical beams where there hadn't been any 90 seconds ago. The glow below these on the actual pictures had a greenish hint to it, showing it may have been green aurora but it was too masked by light pollution for me to be satisfied I was seeing aurora, so I had an idea of a rather more scientific technique of image subtraction. I manually blurred and shrunk the images in paint shop pro and did a subtraction. On enhancing the contrast, and getting rid of a few noise artefacts I got this weird picture. It is a difference picture, so the yellowish cloud is where the cloud was advancing, and the darker blue cloud is where the cloud was. So... I managed to defeat the cloud and light pollution to reveal proof of aurora! What's more I decided to do a rough distance calculation. I estimate the top of the red aurora is 400km high, which is seen at 20º altitude. This leads to a distance 1200km, or a guesstimate of around 800km, allowing for curvature. The green and the red emission of aurorae come from atomic oxygen, but the red is from a higher energy, long lived excited state. This state's energy gets quenched by collisions with air molecules below 100km or so altitude, due to the higher density of the atmosphere.

Thursday, 4 April 2013

Comet PANSTARRS gets even closer to M31

On Tuesday night I placed my 8" telescope, roughly aligned, outside the observatory and attached the Canon 1000D to the photo bracket on top. I was using my old, russian 135mm f/2.8 lens stopped down to f/4. I got a consistent sequence of 83 photos of duration 15" at ISO 800 once the twilight had subsided from about 8:30BST (after having taken away the three where a plane grazed the comet). 15 seconds was the maximum I could get with the RA motor tracking before stars started trailing, because I'd had no time to align the mount. I stacked the pictures using Deep Sky Stacker and after about 10 attempts at processing, removed the gradient. Then I blurred the background and enhanced the faint features by brightening them, hence you can see the whole fan shape of the comet. The total exposure time was just over 20 minutes (with much more time taken up recording calibration frames). Just think... the Andromeda galaxy must look amazing from the comet! :)

Sunday, 31 March 2013

Comet PANSTARRS approaches the Andromeda Galaxy

I popped out to a local hill on the edge of Mousehold Heath within the city of Norwich and took a series of 36 pictures of the comet with M31, the Andromeda galaxy in the frame. Each exposure was 2.5 seconds, and I collected 36 of them. I used the modified Canon 1000D at ISO1600 unguided on a tripod with an old 135mm f/2.8 lens at about f/5. I stacked in Deep Sky Stacker and created a background to subtract manually in Paint Shop Pro. I definitely need more exposure on this one, and tracking. But it clearly shows both objects. It was horrendously cold, so I didn't have the time or the patience to get flat and dark frames. I did spot the comet with 10 x 50 Binoculars in the twilight in the North West and it looked rather impressive, with the tail clearly visible.

Tuesday, 12 March 2013

apologies for lack of activity

Apologies but I'm preparing a talk for an exhibition of all BAS's work on Saturday at Norwich arts centre 2 pm. Also,thrweather has continued to be pretty cloudy. I have another observation to report. A positive sighting of cometPANSTARRS from the lab window through a 5" telescope! It ws tiny dot with a small coma in the deep twilight. Yes! (Apologies I'm using android to enter t this post)

Friday, 15 February 2013

Near Earth Asteroid

After the exciting news of the Russian meteor we finally got to seethe asteroid 2012 DA14. We used the 20" and thanks to our in-house it expert we got to find it between thick clouds. Excited to see the little thing drift through the eyepiece! Sorry no picture this time. Just too much cloud! Time 22:25.

Sunday, 13 January 2013

Fifth moon of Jupiter

I finally found my fifth moon of Jupiter! It's called Himalia, and lives about a degree away from Jupiter in the sky. We recently opened our observatory to the public for three nights, and had clear skies for the last two. After the last people left the dome and were chatting downstairs I set to work obtaining more images of the star field near Jupiter. Unfortunately my Canon 1000D had had a slight mechanical problem, resulting in a brush hair being trapped in front of the sensor. The shutter open-close mechanism suddenly failed to move faster than 1/200" and I tried to clean it with a substandard optical brush. The calibration is a little out. The flat field needs to be updated and also the dark frames I used were from a warmer night. Depsite this, stacking 8 x 30" pictures gave me this interesting image, showing rays of light radiating from Jupiter...and a teency, tiny little dot that was not on the Palomar Observatory Sky Survey red plates. This is Himalia, an outer rock orbiting Jupiter way beyond the four big, bright Galilean satellites that were viewed by many folk earlier in the evening. Some of the visitors got a preview of Himalia on the back of my camera after I had tried to get a few early shots of it. The event was a great success, thanks to the weather holding out and our facilities having been well maintained.

Tuesday, 1 January 2013

A glimpse into Orion's depths.

At last! A snippet of clear sky between fast-changing clouds. Enough to grab a few 30 second exposures of a weird little nebula, IC 426. I turned to one of my to do lists on my phone, that contained unusual objects I wanted to image. I managed to get a moment after a short viewing session at the observatory to whack on my camera, focus on Alnilam, and run off some shots as I dodged the clouds. The moon was rising during the exposures, of which 12 were useful. I got home and processed in Deep Sky Stacker, using some old darks and flats, which I really need to update. Still I got this weird blue thing that looks a bit like the North America Nebula. All I saw on the back of the camera was a wavy line passing between the two brightish stars at centre and winding round like a river on a map. After processing, the rest of the nebula appeared, along with a few other patches. Judging from the colour, this looks like a reflection nebula. The nebula is located to the 'upper left' of the star Alnilam, and the orientation of the illumination seems to fit with Alnilam being the source. So as a first guess, this floating patch of dust could be part of the Orion Stellar Association about 900 light years away [need references].