Wednesday, June 06, 2012

Venus Transit

I wanted to see the Venus Transit, but I don't have a solar filter for my telescope. So I thought that a fun thing to do would be to go to the viewing party being held in town, by the Austin Astronomical Society, UT and Austin Planetarium folks. They were going to have a bunch of telescopes set up on the roof of the Robert Lee Moore Hall at UT, downtown.

In case you don't know, the planet Venus occasionally gets between us and the Sun, at which time we can see it as an eclipse. This happens at rare intervals; the last one was five years ago and the next one won't happen for another 117 years, so if you missed the last one then now was the chance, or not at all.

I arrived just after 5pm, when the transit was starting. The RLM building is 19 stories tall. There was already a long line of people waiting for the elevators, but the staff directed us to the staircase. They had a projection room on the 13th floor for those who couldn't access the roof, but the elevators could only take so many people. Thus it was we all found ourselves getting our exercise for the day, climbing up the stairs... to the twelfth floor, where the line started!

It then took about an hour and a half for the line to slowly crawl up to the 19th floor, where we then had to snake around the corridors before - finally - stepping up into daylight on the roof... There were a lot of people here! I get the feeling they weren't expecting nearly so many folks to show up. However everyone stayed in good humour and there was a bit of a party atmosphere.

My plan was to simply have a look at the transit with my own eyes, and leave the proper photography to the guys with the equipment and experience to do this stuff properly. That didn't mean I wasn't going to try, though!

Here's a couple of the telescopes in use:

This was my first and best attempt at taking a shot by holding the camera up to a telescope eyepiece. I couldn't focus close enough with the camera to match the eyeball distance at the eyepiece. You can see here most of the Sun, with the black dot that is Venus, although it's a bit out of focus. But there it is, look, it's Venus!

They had a pair of binoculars set up, projecting an image back into a shadowed box. This cast a very respectable image of the Sun onto a piece of paper taped onto the back here:

I took this shot and then found a couple of solar filters lying around, so tried a handheld shot with the camera, holding these up to cover the lens. I also used the Live View mode on the camera, so I was looking at the LCD viewfinder, not through the main viewfinder - if the filters slipped, I didn't want to get an eyeful of Sun.

Moments after I got this lot held up, the people behind me looking at the box projection all cheered as an aircraft went through the image. I didn't realise until processing my own images that I also caught it! OK, it's not a fabulous image, but you can see the contrails with a dot in front, and the faint dot of Venus in the 1 o'clock position:

If you want to see what a camera stacked with a long lens and multiple teleconverters could have done, click here! (not mine, obviously)

Here's a couple more of the telescopes. There were a variety of types in use. Too bad the observation dome behind us wasn't in use ;-)

By this time, the staff were urging people to leave if they'd seen the transit already. Apparently the line had now reached the ground floor! There were also clouds moving in, so I hope they didn't all have to leave disappointed. The transit was due to last for six hours in total, but we only got to see three hours since the sun set half way through. I'm glad I went; it was fun.

I leave you with a view of UT and downtown Austin from the 19th floor: