First IOTA Result

The International Occultation Timing Associate is a group of amateur astronomers that measure timing and location of asteroid “shadows” that fall on earth. Sometimes the orbit of Earth and an asteroid line up to block a star that is visible in low-light video cameras through telescopes. Coupling this with a video time inserter that itself uses a GPS timestamp, and the measurements can be calibrated to calculate a shadow shape and size, as well as provide data to help refine the asteroid’s orbital parameters.

I had started on this path a couple of years ago and stalled when I found the “simple” setup doesn’t work well from light-polluted Brooklyn. So I rearranged equipment and found an event involving a bright-enough star that I could see it even from here.

This morning, 2020-09-24 at 8:15:51, the magnitude 9.4 star Tycho 1329-01493-1 was occulted by asteroid 943 Begonia. And I caught it on tape. Visually, it’s pretty cool to see the star suddenly blink out and then reappear a few seconds later.

The above is a preliminary analysis. I’m still feeling my way through how the data is reduced for reporting. The pink/magenta data is a reference star, the blue is the occulted star, with the disappearance highlighted in red.

I’m sleep-deprived, but very happy right now, it worked!