Arp 155

ARP 155 2017 Mar 21

Object: ARP 155 (NGC 3656 & companion) Date:            2017 March 21
Peculiarity:    Disturbed with interior absorption.
Constellation:           Ursa Major Time & altitude:   21.45 UT       75º
Catalogue data: Seeing (5 high):                               3/5
            R.A:                11h 24m Transparency (5 high):                3/5
            Dec:                53º 50 Telescope:     0.5m f4.1 Dob.
            Magnitude:    12.5 Eyepiece:      8mm Ethos      x260
            Galaxy size (mins):  1.6 x 1.6 Filters:            None.


Conditions looked promising to the unaided eye but were not that special through the telescope.

This is a conspicuous galaxy. It is round, but missing a segment on the side opposite to the adjacent 12th mag. star. The half of the galaxy next to the star has a well-defined ‘hard’ edge. The opposite edge is more diffuse.  There appeared to be some fine linear striations running across the galaxy E-W. There is no core.

Arp’s Atlas shows a tiny companion galaxy on the S edge of Arp 155. It was not seen.