This is the three prominent stars in the Eagle constellation (Alshain, Altair and Tarazed), with nebulosity from the Milky Way on the right side.
Right next to Tarazed is "Barnard E" dark cloud, easily recognized from its shape, but which I didn't know of at first.
There's an unknown artifact above Altair and Tarazed.
Though it looks like it with its greenish color, from general advice this was not a comet, but would rather be a lens' reflection (though I never had this kind of reflection with this lens in other shots -- in fixed position in the subs while all the FoV was moving slightly)
Gear: Olympus E-PL6 with Minolta MD Rokkor 50mm/1.7 at f/4.0 and didymium filter on Omegon EQ-300 tracking RA
Capture: 3 lights x 60s x 1600 ISO, master dark
Site: near country 50km from Paris, France
Sky: nearly good, no moon
Processing: Regim 3.4, Fotoxx 12.01+