Object of the Week May 28, 2017 - NGC 5953/5954 (Arp 91)

NGC 5953/5954 = Arp 91 / VV 244 / KPG 468 / Mrk 1512

NGC 5953
RA: 15 34 32.3
DEC: +15 11 39
Mag (V): 12.0
Size: 1.6' x 1.3'

NGC 5953
RA: 15 34 34.9
DEC: +15 12 04
Mag (V): 12.2
Size: 1.1' x 0.5'

Both galaxies were discovered by William Herschel in 1784.

Since then they found entry in the famous catalogues like the “Vorontsov-Velyaminov” (VV 244) or Arp (91). Arp sorts both galaxies in the main group: “Spiral Galaxies” with the sub group “companions on arms – large, high surface brightness companions”.

Only a few scientific papers describe this pair. The same distances (25 Mpc) and the appearance indicate a galaxy-galaxy interaction. NGC 5953 is a Seyfert 2 typ and host an active galactic nucleus (AGN). The combination of an AGN and the interaction results massive star formation and shows interaction sign like bridges and plumes.

Visually both are in reach of small to mid size telescopes. The small size is the problem - with 1.5’ lateral extension, the group has only ~1/5 of the pair M 51/NGC 5195. High magnification is the key to detect the details. With larger aperture the bridge, the HII regions in NGC 5954 or the faint plume north of NGC 5953 could be the challenge. For lovers of faint companion galaxies UGC 9902 is located 3.8’ south of the pair.

DSS blue 15'x15'
Attachment 2569

ING (WHT) Knapen/Szymanek
Attachment 2570

sketch: 27", 419x-586x, NELM 6m5+
Attachment 2571

As always, give it a go and let us know!

Hi Uwe,
I actually observed this pair on may 21st with typical conditions in the Münsterland. Here is my sketch with 24" at 252x magnification.
Attachment 2572

I definitively have not the conditions you have, although some structure was noticeable...

As Uwe mentioned, both are within range of mid-sized telescopes. I have seen both with a 13" back in 1993. Yes, high magnification (240x) does help.

This is an impressive field with 5951 (16" F/4.5, Cherry Springs State Park, 2011):

"NGC 5951. Very strongly elongated (~4:1). Shares the 24-mm field (~30’) with NGC 5953 and 5954. The last two are touching. 5953 is small, round, bright. 5954 is of equal magnitude, but more spread out, elongated (2:1), same length as the star pair nearby, but more inclined toward 5953 than the segment between the stars is. Same view at 8 mm and with the 6 mm Abbe II."