"Crab Nebula," the Movie

[Dick Berg]

With such an intriguing title as that, you're probably expecting some feature-length, full color, hi-def movie of the Crab expanding, or something. Sorry to disappoint you.

Last night I took images of the Crab for fun, without realizing that the asteroid 3724 Annenskij was moving through the field. It's a little past opposition and retrograding, at a distance of about 160 million miles, and visual magnitude 15.3, according to the Minor Planet Center.

I put together an animated .gif showing this swiftly moving asteroid. I spent considerable time fussing with each image to get the nebula to have the same surface brightness in each image. That came out pretty well, but along the way somehow the overall brightness was reduced considerably. The .jpg image shows the stack of the eight images.

The animation runs slightly less than two seconds. Needless to say, if I had known the asteroid was there before I started, I would have made a feature-length movie.

[Bob Denny]

Neato!!! And you're right, the rest of the field is perfectly still (ho brightness changes). Fine job!

[Russell Archer]

Hi Dick

Really excellent animated GIF!

I tried something similar (deliberately) about a year ago. I used Starry Night 6 and ACP Planner to create the ACP plan, and was very surprised to see I had actually captured an asteroid where it was predicted to be!! The animated GIF below is simply made of up of the 'raw' images - I didn't do any flats, and you sure can tell with the vignetting and dust donuts :-)

My attempt simply has an asteroid moving through a 'boring' star-field. How wonderful to have M1 as a backdrop to the asteroid - thanks very much for sharing it

Russ

[Dick Berg]

That's neat, too, Russ.

I cranked my SNP back to your date and found Atalante right there! Of course! But because of our difference in longitude (and therefore parallax), at the midpoint of your series, about 1800 UT, at the conjunction, from my viewpoint the asteroid is much farther to the east, about twice farther east as your easternmost image. And it would have been noon here.

I notice that this was also a really close conjunction, but it doesn't appear to be an occultation of the background star. There's a really active occultation program here in the US run by David Dunham (here: http://www.lunar-occultations.com/entersite.htm, or here: http://www.lunar-occultations.com/iota/iotandx.htm) that you might find interesting. Occultations like this are extremely useful, especially when multiple observers watch then, as they describe chords which in turn describe the shape of the asteroid.

Anyway, I like your movie too! We could have a film festival someday... :-)

[Russell Archer]

Hi Dick

Glad you liked my little movie. And many thanks for the links to the occultations sites, I'll certainly investigate further.

I know it's all obviously and unsurprising, but I found it really magical that the asteroid was *exactly* where SNP said it would be, and that later on ACP found it and imaged it for me! True science fiction stuff really

Russ