Galaxtic interactions - NGC 772 and NGC 770

[gorann]

This is what Wikipedia says about the odd locking NGC772:

Around 200,000 light years in diameter, NGC 772 is twice the size of the Milky Way Galaxy,and is surrounded by several satellite galaxies – including the dwarf elliptical, NGC 770 – whose tidal forces on the larger galaxy have likely caused the emergence of a single elongated outer spiral arm that is much more developed than the others arms. Halton Arp includes NGC 772 in his Atlas of Peculiar Galaxies as Arp 78.

The sky is too light up here (and rapidly getting lighter) so this is of course data I processed (in PS) from the Liverpool Telescope (a 2 m RC on La Palma) that keeps me occupied.

Data:

40 x 100 s through Bessell B (blue channel)

28 x 100 s through Bessel V (green channel)

18 x 100 s through sdss-r (red channel)

No Ha available so this is RGB

Comments of course welcome

[wimvb]

I like the red streak (spiral) counter balanced by the blue spiral arm. The galaxy would be dull without. Nice work.

[gorann]

15 hours ago, wimvb said:

I like the red streak (spiral) counter balanced by the blue spiral arm. The galaxy would be dull without. Nice work.

Thanks Wim! This one is a step up from the tractor wheel galaxy (M88) I just processed - I think NGC722 is quite a bit more 3D. I get the impression that NGC770 (top centre) is tearing apart and sucking in that spiral arm in bits and pieces.