Any ideas on this one?

[AJ]

I am in Cincinnati(east side) and caught this sequence early morning Labor Day. I did a more thorough search than I did for satellite A02 (as remarked in SNP6) which had me perplexed for days. I can't find anything reasonable in the vicinity of Orion that morning. So what is it? The frames are over- exposed(in photoshop) to bring out the object in question, and I applied a grid just to give a sense of distance. I assume its just an asteroid, note the distance traveled in the short time, and the noticeable spin. Also I noticed that there seems to be no reflected light. Just a shadow. I am sure it was no bug, as this is cut from a larger set of pics, which I stacked, aligned, and cropped.Enjoy!
From left to right, exposure times are 60, 90, 120 secs. shot with Canon 400D(stock) with a 75-300 F/4.5 with a 2x tele-converter shooting at F/5.6. Tracked using a Celestron CG-5ASGT

[apodman]

Bird.

Whatever it is, it traveled 4 grid boxes in 1:34
and then only 2 grid boxes in 2:10, so its speed is not constant.
I doubt that the changing viewing angle alone could account for a
difference that large. It also does not follow a straight line.
It also stays roughly the same size from one frame to another,
suggesting its altitude didn't change much.

And which APOD is this qustion about?
I thought this forum was about APOD.

[AJ]

I posted because of todays apod, I noticed how bright Steins is. thats a slow flying bird to have only crossed that smal field of view in over 4 minutes. I apologize if this is against TOS, remove if offensive. Will post in Astromart and Cloudy Nights. See what the pundits think. Sorry again.

[Chris Peterson]

I am in Cincinnati(east side) and caught this sequence early morning Labor Day...

It may be something on your sensor, or on the optics close to the sensor, or it may be something floating not far above you.

Whatever it is, it isn't above the atmosphere, since it is clearly a shadow against the skyglow. Nothing in space can be darker than the sky background.

[henk21cm]

From left to right, exposure times are 60, 90, 120 secs. shot with Canon 400D(stock) with a 75-300 F/4.5 with a 2x tele-converter shooting at F/5.6. Tracked using a Celestron CG-5ASGT

In support of Chris Pettersons analysis, the dark object itself is stationary during the exposures. The dark blob is in all three images of equal size, while the exposure times increase by a factor 1: 1.5: 2. If the object was moving with respect to the stars, the blob in the 120 s exposure should have been longer than in the 60 s exposure.

Dust particle, paint flake, a blister of a seed inside the optical system or a spider is my guess.

[AJ]

Very plausible. Would have to be a very small one inside the camera body if so. Thank you.