More Shadow Chasing

It's only a few days before Endeavour undocks from the ISS and returns to Earth. Unfortunately, there are no solar transits visible from the UK after undocking, so this imaging session was to try and improve on my previous "docked" image. Endeavour is the dark blob situated between the solar panels, which are also better presented compared to my last post. I was chuffed to get 4 images so, overall, I think this is a more pleasing composite than my last effort. Images taken at Maple Cross, Herts. on 24th May.

Due to the resolution limitations of my camera and lens (420mm), I think this is the best I can achieve with my current set-up. In the raw images, the ISS is only about 25 pixels across, so there's not much data to play with! I need to increase the image scale which means getting one of my scopes set-up for solar imaging. Another project to add to the growing list.

ISS/Endeavour at 10h55m and the all important 24seconds.... (and sunspot 1216)

A very fuzzy Endeavour

Shadow Chasing - Endeavour crosses the Sun

After yesterdays disappointment, the weather today was forecast to be worse, but I checked out a favourable spot anyway to try and image the ISS and Endeavour transit, predicted for this morning at 11.43 and 38 seconds. I've only got 3 attempts left to try and image Endeavour before it's pensioned-off, so I had to try and hope for better luck than we had yesterday.

When I arrived at my chosen site near Pulloxhill, Beds, I parked up in a convenient field ......and it started to rain. "What am I doing here?" I asked myself. As the wind was blowing the cloud along at a fair pace I thought I'd stick it out and hope for the best. Fortunately, 10 minutes before the transit started a big patch of blue blew across the sun and everything was looking good.

No other mishaps, and I started my 100 exposure sequence 10 seconds before the predicted start, at a rate of 5 fps, using my laptop on the car seat to get an accurate time fix.

Back home, I was delighted to have captured 3 images which are composited here. The other dot on the sun is the sunspot AR 1216. The enlargements show some detail - one of the sets of solar panels is very clear, though I'm not 100% sure which bit is Endeavour. I suspect it's the dark blob near the centre.

Duration of transit only 0.57 secs. Shadow ground speed 7.5 km/s

Diameter of ISS = approx 65.4 arc seconds

In a field somewhere, with my DSLR and 420mm lens



Nice cuppa, shame about the cloud

Would you believe it.

My pal Dave and I set-up our gear in his garden, in glorious sunshine, and awaited the ISS transit predicted for 9.45 this morning, with DSLR's and webcams at the ready. With about 1 minute to go, the only cloud to cover the sun during the whole morning slowly moved across the solar disk and we were plunged into shadow. I started exposures as I'd planned anyway - starting 10 seconds before the transit - in the hope that a break in the cloud at the crucial second of transit might appear. Sadly, no such luck and, as if to poke fun at us, the cloud slowly moved away from the disk 10 seconds after the end of the transit! The sun appeared on only the last few frames of my 100 exposure sequence. "Oh dear, never mind" we said to ourselves!

Oh well, the cuppa helped calm the stress and frustration at having missed the event.

Dave's superb observatory with my modest DSLR in front

The offending fluffy stuff

Peekaboo - 10 seconds after the end of the transit!



The one that got away...

Motivated by my previous ISS transit success, I thought I'd have another try today. The centreline was predicted to pass through a local nature reserve (Paxton Pits for those that know it) so if I was clouded out at least I could try and photograph some interesting wildlife.

With 30 minutes to go, things began to look dodgy. I rattled off 15 images to check my exposure settings and then waited impatiently. To my dismay, the clouds won the day and with 15 minutes to go there wasn't a patch of blue anywhere to be seen.

This image was taken from the 15 test images and shows some minor sunspot activity and a bit of faculae, so all was not lost.

Oh, and I didn't get any bird pictures either. Some days are like that, aren't they? Anyway, trying again tomorrow, as there should be an ISS transit visible from my friends back garden....weather permitting. At least we can have a cuppa while we watch the clouds roll in!



No, not the ISS - just a few sunspots.



ISS Transit ID

Following some searching on the web, I've tried to identify the different parts of the ISS that (with a small stretch of the imagination!) can be seen in my image of a few days ago. The solar panels can be rotated to suit the sun's position relative to the station, and are shown at a slightly different angle between the two dates.

As a rough guide to image scale, the area covered by the four sets of solar panels is 361 ft wide x 240 ft long.  The station was imaged at a distance of around 250 miles. As best as I can estimate it, the theoretical resolution on the original image works out at roughly10ft per pixel.

ISS Solar Transit - 13th May 2011

First time I've tried to image the ISS crossing the sun. Seen lots of great images on the web, but naiively thought I'd need more sophisticated gear than I currently have.  Anyway, while browsing the web last night, I happened to check the ISS transit programme on CalSky just for interest. I was surprised to see that the centreline of the next transit was today, a mere 3km from my house. Too good to be true I thought, so I decided to give it a go and hope for the best. The total transit duration was predicted to last only 0.5 secs, so my timing needed to be pretty accurate.
Anyway, here's the result. I have to say I was dead chuffed. The close-up clearly shows the solar panels, with the station modules lying between, at an orientation of what looks like approaching end-on.

Details - 420mm telephoto with Baader solar film. 1/1250s at f8. 100 images taken at 5fps starting 10 seconds before the predicted start of transit.



Composite of 3 images taken 0.2 seconds apart