Ok, so Venus isn’t an extrasolar planet (exoplanet), but I thought this would be a cool thing to try. A while ago I put together a time-lapse movie of the 2012 Transit of Venus. More recently, during a public talk on exoplanets, I saw a video someone had made to demonstrate the transit method used to detect planets around other stars. The video looked a bit like my time-lapse, except that it was a simulation. I thought, “why not try to get a real light curve from my transit footage?”
After far more fiddling around than I was prepared for, you can see I just about managed it. It really goes to show how sensitive astronomical instruments are, when we are seeing transits elsewhere in our galaxy but a bunch of 10 megapixel photos of the sun are almost too noisy to extract a signal.
I love this technique though, because it’s so simple. It’s how the Kepler spacecraft has (so far!) spotted over 1500 planets orbiting distant stars. I made this little video not only to see if I could, but because I think it’s a nice ‘real life’ (sorta) demo of the transit method, good for introducing the topic to a non-specialist audience. It can be downloaded from Vimeo. I also made animated gifs for endless looping fun (thanks to Hugh Osborn for the idea).
Big GIF (800 px, 26.7 MB): https://labjg.files.wordpress.com/2014/03/transitplot_800.gif
Med GIF (640 px, 17.9 MB): https://labjg.files.wordpress.com/2014/03/transitplot_640.gif
Small GIF (480 px, 10.4 MB): https://labjg.files.wordpress.com/2014/03/transitplot_480.gif