Saturday, June 9, 2012

Images from My Transit of Venus, June 6 2012

My first image of Venus at 10:26 am ACST when the clouds had broken.Near mid transit at 11:04 am. The varying colours are due to the cameras auto exposure function, and its lag when clouds come over.
After a cloud interlude, Venus approaches the Sun's limbJust before 3rd contact at 1:52 pm ACST

I had great plans for the Transit of Venus on June 6 2012, the last until 2117. I had made a binocular projection system, I had my 4" Newtonian telescope with a glass aperture solar filter, a home-made Baader filter for my 8" Newtonian telescope and a mini Baader filter for my Olympus camera.

Wednesday dawned cloudy. Actually, when I first woke up the sky was mostly clear, but huge slabs of cloud moved over where the Sun would be shortly before Sunrise, ending any hope I had of seeing first and second contact.

This was the pattern for the day, large parts of the sky would be sparkly blue, except where the Sun was. Due to the weather I made a decision to only use the binocular projection system and my 4" Newtonian scope, as these systems could be moved around a lot more quickly than the homogeneously heavy 8". Also, although I have a time drive on the 8", it drifts slowly. With brief patches of blue coming over the Sun at short, widely spaced intervals, the time to realign the scope would be too long to catch the breaks. So I stuck with the simpler systems.

An added complication was that SmallestOne was sick and had to stay home too. He wasn't THAT sick, well enough to watch TV and play computer games, but I still had to keep an eye on him and give him his medications at the prescribed times. So I divided my time between moaning at the clouds, looking after SmallestOne, watching the live webcasts and rushing out when gaps in the cloud came up.

I had a great Transit. I took heaps of shots through the 4" scope. Most were useless, with cloud coming over just as I was imaging, or the scope shaking with the wind. Getting the focus right was a pain too. But I could watch the progress of the transit with the binocular projection system easily while I fiddled with the camera.

Some people came over and I showed them the transit with the projection system (I had to move quickly to stop one person trying to look through the eyepiece rather than at the card the image was projected on. Even SmallestOne came out and had a look (he wasn't impressed). Compare this transit with my Transit experience in 2004.

Even though I thought I had carefully placed my scope, just as third contact was coming up, the Sun went behind a tree. So I rapidly moved the scope and binoculars, and hurriedly realigned and refocused in time to see Venus approach the Sun's limb.

And the clouds came over again.

Nonetheless, I was able to get sufficient shots to see third contact and just before fouth contact (I though I had 4th contact but I was fooled by the low magnification image). I have made the final series of images into the animation below. It's a bit jerky as at lot of frames were unusable due to cloud. The weird tiny black speckles are due to the GIF to AVI translation. Images taken using infinity to infinity imaging a Canon IXUS and a 4" reflector with aperture filter and 25 mm eye piece, the camera was held in place by a commercial adapter (see image of the scope above).


Animation of third and fourth contact. Images were imported into GIMP as layers, aligned using the difference function and manual alignment, the cropped, exported as an animated GIF, then converted to AVI with ImageJ.

Reflecting after it was all over, what was really good was the degree to which  the astronomical community, both amateur and professional, put a lot of time into  making sure the general public got to experience the transit, either by making their won projection systems, public outreach events or webcast. As well as thoroughly enjoying my own experience, I'm glad I could help in some small way to let others experience it.

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