Strange slow trail through M31 , NEO ?
Posted 08 September 2012 - 08:21 AM
Each frame is a 60 second exposure and the FOV is roughly 4 degrees ( ED80 + F/F ) centred on M31 , 1st frame at 22:10 UTC , last at 22:22 UTC. Observed from 52.29963N - 0.49924E.
Was far too dim to pick up in bins and too slow for a satellite methinks !
I've had a quick look at NASA's NEO site but got a little confused to be honest , maybe someone could input the details correctly for me , I'd be very grateful .
Posted 08 September 2012 - 04:22 PM
Posted 13 September 2012 - 04:55 AM
Just by examining the sequence of your images, and picturing in my mind the geometry, I'll make a provisional analysis as though this were asteroidal. Again, this is purely hypothetical, based on mental 'back of the envelope calculations!'
It's motion is prograde, its orbit is tilted roughly 50 degrees to the ecliptic, and it very recently (within the preceding day) crossed the ecliptic going northward, meaning it crossed the ascending node.
The orbital inclination would depend of course on the relative speeds of Earth and the body; if the body is not so much faster, the inclination is steeper than 50 degrees, and if rather faster, the inclination is shallower. In any event, given that it's roughly opposite the Sun and is overtaking Earth, its orbit's semi-major axis is larger than 1 a.u., and it is on the way to perihelion, being closer to that point than aphelion. It's orbit certainly crosses the Earth's, and it spends rather more time outside Earth's orbit than inside.
Again, this is all hypothetical! If asteroidal, the fairly large angular motion implies a quite close passage at the time of your images. And given the nearness to the ecliptic plane would make this a *potentially very dangerous* Earth crosser!! And so such a fairly bright body must already have been discovered, which leads me strongly to the great likelihood of it being man made...
But you never know! Keep pressing for identification if man made; if nothing is forthcoming on that front and you've exhausted all avenues, be prepared to submit your data, including your best determinations of time.
Posted 13 September 2012 - 01:46 PM
Posted 15 September 2012 - 07:06 PM
I'm really grateful for the time you've put in , it's humbling to be amongst people that know their stuff on here.