Geminids

I've never tried to image meteors before, but this was supposed to be a reasonably good shower so I braved the sub-zero temperatures for an hour or so and tried my luck.
Although some of the meteors were quite bright to the unaided eye, I had to progressively crank up the ISO setting to record anything at all, ending up at ISO3200 using an 8mm wide-angle at f4.5. At this high sensitivity I knew the sky-glow would be difficult to keep under control, so limited myself to 10 second exposures.
Of the few hundred images taken, I was chuffed that a handful had the tell tale streaks of meteors.

This image is a composite of several of these. It was a job to orientate and register the separate images correctly, since the constellations distorted due to the wide-angle lens as the stars moved across the sky.
The red lines show the tracks of the meteors converging back to their origin, as best as I could estimate these, to show the region of the radiant. The variation in radiant positions is due to the distorting effect of the lens making it impossible to accurately represent the curved sky on a 2-dimensional flat image, for meteors that were widely separated on the image, but they appear to radiate from just NW of the star Castor, the head of one of the twins.

What a whopper!

AR2192 is the largest sunspot of the current solar cycle, and is the largest seen since 2001. Spanning around 124,000 miles across, it could easily swallow the planet Jupiter.



25 Oct 2014

AR2192

Kelling 2014

A few images from the Kelling Equinox Starparty taken on 27th Sep. The previous night was the clearest, which unfortunately I missed, but the Saturday night was still clearer than I get back home, and it was great to spend time with good friends.

Some nice sunspots. Like the forgetful person that I am, I went and left my solar filter at home, so had to borrow an oversized filter from my good pal Dave. Lashings of sticky tape did the trick at securing it to the front of my DSLR lens, to enable me to shoot the 30 or so images needed to make this Registax processed final image, with final tweaking in Photoshop.

I'm not very experienced at deep sky imaging, but thought I'd try some unguided wide field constellation images.

Andromeda. 20 x 15 sec stack. 50mm f2.8. Processed in Deep Sky Stacker, with further tweaking in PS. Not the greatest image, but pleased to capture M31. M32 and M110 are also just visible.

Pleiades and Hyades. 8 x 10 sec stack using 50mm f2.8

Winter Sun - 11th Jan

AR1944 is one the largest sunspots of this solar cycle, and was responsible for a large CME a few days ago that brought impressive aurora displays in the arctic. It was hoped that the storm would be powerful enough to produce more southerly displays of the northern lights, but sadly this wasn't to be. Never the less, the sunspot is pretty impressive on it's own.

This is the first solar image I've taken for over a year and it was tricky to remember what settings I normally use, and how I usually process the final images.

This was a stack of 20 images taken at ISO 200, 1/2000, f8, through Baader solar film using my trusty Nikon D300 with 300mm telephoto and 1.4 converter, giving a total focal length of 420mm.

Images stacked in Registax 6 and processed in Photoshop CS2.

California Dreamin'

When I first became interested in astronomy as a teenager, I used to marvel at pictures of the famous astronomy sites in California, not imagining that I'd ever get the chance to see them with my own eyes. To me they were iconic - some of the biggest telescopes in the world; landmark observatories known for some of the most famous discoveries by world renowned astronomers and, of course, the most famous meteor strike in the world.
Well, this summer, I finally had the opportunity to visit some of these places that I'd known since childhood as mere images in books, and I wasn't disappointed.

Mount Wilson's 150 foot Solar Tower telescope

150 foot Solar Tower telescope

Dome of the 60" telescope, largest in the world when it was built in 1908

Dome of the 100" Hooker telescope

100" Hooker telescope, the largest in the world until 1948, famously used by Edwin Hubble



Viewing gallery for the 100"

Dome of the 100" Hooker telescope

Panoramic image of the Barringer Meteor Crater, Arizona

Meteor Crater visitor centre amidst the desolate Arizona desert

 

The Pluto Discovery astrograph, used by Clyde Tombaugh

Rotunda library "Saturn" lampshade

Blink comparator, used by Clyde Tombaugh in 1930 for the discovery of Pluto

Pluto discovery telescope observatory

The "Mars" telescope observatory

24" Alvan Clark refractor famously used by Percival Lowell to study the Red Planet

Percival Lowell mausoleum in the shadow of the Mars observatory

Northern Lights

Tromso, Northern Norway, 69 degrees north.

Friday 8th Feb - Soon after arriving at our hotel on the harbour in Tromso, we were amazed to see the lights on our first night.  Unfortunately, having only just arrived, despite having hired a car we didn't yet know our way around to try and find some darker skies, so decided to enjoy the lights as best we could from the harbour wall just by the hotel. We weren't disappointed and although the glare from the buildings was brighter than I'd have liked, we still saw an impressive display. At one point the lights shot across the zenith right over the hotel.

 

Saturday 9th - The website forecast I'd been following suggested the aurora was going to be brighter than the previous night so we were getting excited as evening fell. Unfortunately the clouds rolled in. Despite driving to darker sites away from Tromso, the skies didn't clear beyond a few small breaks and we sadly didn't see any sign of the lights, which was disappointing.

Sunday 10th - patchy cloud throughout the day grew to total cloud cover by sunset at 4.30 so, after evening dinner, we retired to our room and watched for breaks in the cloud on the Tromso all-sky internet webcam. At around 7.30 a small break in the clouds started to appear and I saw a hint of green. The last few nights experience had told me that aurora seen with the naked eye was less bright than shown on the webcam. Nevertheless, as the sky continued to slowly clear, we decided to give it a go, rapidly climbing into our arctic gear and heading for the car. We drove to a small parking area on the other side of the island which we'd previously noted as offering dark views to the north despite it being very close to the airport.

I took a few test images to see if I could see any sign of the aurora, and could just about make out a hint of green, although this wasn't visible to the naked eye. We waited. About 30 minutes later, the clouds miraculously blew over, revealing a clear starlit sky and a pale auroral band to the north.

As we watched, and I started taking images, this suddenly brightened and a bright band grew up from the western horizon to cross the zenith down to the eastern horizon, rippling along the edges. Amazing. After that, the whole sky just erupted, and we didn't really know where to look. Vivid green bands of rippling light danced over the whole sky. Rapidly flickering red and green needles of light began to appear along the edges of the bands. Absolutely stunning.

All images - Nikon D300, Sigma 8mm f5.0, ISO1250, 10 second exposures.
Using an intervalometer I set the camera to take 10 second exposures at 15 second intervals. Here is the resulting short video sequence of a number of these. I now wish I'd taken more between moving the camera to get a longer movie. I guess I'm just going to have to go back and have another go!

Activity on the increase

Sun-spot activity continues to increase towards solar maximum next year.

In a rare gap in the torrential rain and total cloud cover that seems to be the British Summer this year, I couldn't miss the opportunity to try and get a few images last Sunday. Fortunately, active region 1520 was still putting on a show, following the CME that smashed into earth's magnetic field on the 14th.

I was pleased that, following my failure to get the camera settings right during my last imaging session, this time things seemed to go a little better, remembering to set the ISO below 200.

Processing was my usual routine - 20 RAW images, stacked in Registax 5 with tweaks to the wavelets and de-ringing (more by trial and error as I'm far from mastering the various options). In Photoshop CS3 though, I thought I'd be bold and experiment a little. The two images are processed in largely the same manner, differing only in the blend mode applied to a copy of the background layer as output from Registax. I'm not sure which one I prefer.

Blend mode "Lighten"

Blend mode "Multiply"

What a whopper!

Sunspot active region 1476 that is. A rare spell of sunny weather over the weekend allowed me to try and capture AR1476, which is the largest active region so far this solar cycle.

Unfortunately, it's been a while since I've used my camera and I must've been a bit rusty in it's basic operation, leaving the ISO setting on it's previous value of 800. As if I needed that extra bit of sensitivity to record the solar disk! I should've realised things were not right when I found I needed an exposure of 1/5000 to prevent over-exposure, but this clue clearly escaped my attention, so ISO800 it remained. I only realised my mistake when processing the stack of 20 exposures later on Saturday evening.

Considering the noisy settings, the final result is actually not too bad. I presume the stacking in Registax has helped remove much of it, but I still wish I'd had opportunity to repeat the shots at my usual ISO200.

Twilight Parade

I love the beauty of the crescent Moon with the faint Earthshine glowing against a slowly darkening twillight sky. When moving against a backdrop of planets, the view can be magical. And so it was on the night of Monday 26th. The three brightest objects in the sky (apart from the Sun that is!). Venus at the top, with fainter and more distant Jupiter hovering above the branches of the bush. Wonderful.

Conjunction 2

The closest approach of brilliant Venus and Jupiter was unfortunately clouded out this evening. Good job I imaged the two brightest planets a few nights ago then, when separated by a little over 3 degrees.



Jupiter & Venus over Willington



Back to the Sun

Sunspot AR1429 has been responsible for recent coronal mass ejections (CME's) which have been battering Earth today, with another geomagnetic storm due to reach Earth tomorrow. Watchers in northern regions have been enjoying some marvellous aurorae, but sadly few have been visible from Bedfordshire. Hopefully chances of seeing the lights from Britain will increase as activity continues to increase towards solar maximum next year.

A while since I've imaged sunspots, so today I thought it was high time I went back to the Sun.

Conjunction

After several months of inactivity on the blogging front - partly due to my PC being out of action - time for a quick update.

Venus is putting on a fabulous show at the moment, shining at a brilliant magnitude -4.1. This is the conjunction with a lovely crescent moon on the 25th March, the two brightest bodies in the night sky being separated by only 3 degrees.



Earthshine



 

Cracking Sunspots

Some of the best sunspots of the new solar cycle so far, taken this morning, 31st July.

Imaged through my normal set-up of D300, 420mm telephoto (300 + 1.4 TC) and Baader solar film. 20 images stacked in Registax and colourized in Photoshop CS3.

Forgot to label the image whilst processing, so - the 3 main spot groups (from bottom to top) are active regions AR1263, 1261 and AR1260. AR1265 is the small single spot to the upper right of AR1260.



AR1263, 1261, 1260 (bottom to top)



Last Voyage of Atlantis

The very final Space Shuttle journey into orbit.

According to CalSky.com there are several solar transits this week, creating some last-chance imaging opportunities. Ideally I wanted to try and image Atlantis as a separate object to the ISS, as it's tricky to reliably identify once it's docked. So, all that was needed was a transit to occur either just before or just after docking, some clear skies for the critical second, and knowing where to set-up my camera gear.

By good fortune, CalSky.com was predicting a pre-docking transit with the centreline crossing England just north of Corby for early afternoon on Sunday. So, armed with camera's, scopes, laptops and a sat-nav, my mate Dave and I headed off in good time to set-up. Using Google maps, we'd identified a convenient entry into a field just north of the village of King's Cliffe, so off we went.

Cloud cover was a major worry and initially hampered Dave's attempts to find best focus through his scope, but as transit time approached the clouds began to clear and the adrenaline started pumping. For those who haven't tried transit imaging, the emotions are hard to describe. The transit was predicted at lasting only 0.56 seconds, so everything had to come together exactly at the right time. No second chance. Camera alignment, focus settings, self-timer settings, exposure settings being changed down to the last second to compensate for varying cloud cover, clock-watching to get the start of automatic exposures timed just right. And of course - would the clouds be clear of the sun for the critical second. Excitement, anticipation, panic, nerves, apprehension.... they're all there.

I'm pleased to say it all came together - here's the results.

Details -

Size of ISS = 60.1".
Distance from camera to ISS = 460km.
Transit duration = 0.59s
Images taken 2h 27m before docking.

Nikon D300 + 420mm telephoto + Baader solar filter.
Continuous exposure settings set to take 5 fps for 20 seconds at 1/1600s and f8. ISO 200, starting at 13.39 and 44 seconds BST.



A field somewhere near King's Cliffe




Worry - will the cloud spoil the day?




ISS at 13.39.56 seconds (2 image composite)




Close-up, passing across a field of sunspots




Atlantis - spot it if you can!




Atlantis 13.39.58 seconds (2 seconds behind and in hot pursuit of ISS)




Close-up! Passing between sunspots AR1249 and 1245




Path of ISS and Atlantis.