Background

I was checking Stellarium to choose the next target to image and noticed that Vesta was in a convenient patch of sky. This asteroid is bright enough that it shines through even light polluted city skies. It moves fairly speedily compared to the background stars, so if I could get images of it over a few consecutive nights I’d have enough material for an animation.

The weather was pretty bad, but there were enough gaps in the cloud to get at least one 120-second sub each night. To get the framing right I noted the the RA/DEC of the asteroid’s location in the middle of my predicted five-day run, then used my ASIAIR PRO to move my telescope to those coordinates each night. This made alignment quite easy.

Actually identifying Vesta was quite tricky though. I used the Blink function in PixInsight to quickly flick through the images in order to spot the one dot that was moving relative to the others. In the end I needed to crop in quite tight for the final images — although Vesta is speedy, a 400mm telescope and APS-C camera sensor easily captured it over five nights with plenty of room to spare.