Arp 336

ARP 336 2015 Feb 21

Object:   ARP 336   (NGC 2685) Date:               2015 February 18
Peculiarity:    Unique.
Constellation:           Ursa Major Time & altitude: 22.50 UT     82º
Catalogue data: Seeing (5 high):                               4/5
            R.A:                8h 56m Transparency (5 high):                   4/5
            Dec:                +21º 53 Telescope:     0.5m f4.1  Dob.
            Magnitude:    11.2 Eyepiece:      8mm Ethos     x260
            Galaxy size (mins):  4.5 x 2.4 Filters:            None.


An easy object. Named The Helix Galaxy, it is a rare polar ring galaxy where disturbed material orbits perpendicular to the plane of a flat galactic disk. I am seeing the disk as a long rectangle 3:1 or 4:1 aligned NE-SW. There is a bright nonstellar nucleus. I do not see any evidence of the outlying ring structure. However, the core is mottled throughout; more so at the NE end and this could be due to the rings seen in silhouette against the disk.