Re: Challenge object: Tiny faint galaxy grouping in Ursa Major
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If you zoom the posted image, there are two "spiral" trails, one much fainter than the other, side by side. The faint trail extends farther toward the bottom of the frame than the bright one -- in fact, off the frame -- which I suspect makes it unlikely that one trail is an optical or processing artifact of the other.
If the object(s) is(are) actually "spiraling", the rate of rotation is awfully fast -- remember, the lateral motion is at orbital speed, likely at an angular rate on the order of a degree per second as seen from the ground. Might alternatively be something rapidly flashing, reflecting off something ring-shaped.
How far off the zenith was the line of sight for the images? Knowing that, and remembering that an arc second is about one meter at 200 Km, and assuming that it is high enough to be in orbit, would give a lower bound on the size of the thing.
Could it be closer than in orbit?
I think the big mystery is, that there appear to be two of them..
On Apr 27, 2022, at 6:54 PM, Roland Christen via groups.io <chris1011@...> wrote: