In Search of Interacting Galaxies (Part 2) -- 6 June 2014

[Steve Gottlieb]

Here's the last two objects of the observing report ---

NGC 5256.jpg
NGC 5256
13 38 17.6 +48° 16’ 37"
V = 13.2; Size 1.2'x1.1'; Surf Br = 13.3

This galactic train wreck appeared fairly faint to moderately bright, fairly small, elongated 4:3 SW-NE, 40"x30", brighter ill-defined core, uneven surface brightness. Occasionally, a brighter quasi-stellar knot (nucleus of the merged companion) would pop on the northeast end of the glow! HJ 2667, a wide pair (14") of mag 11 stars, lies 5.6' WSW.

This colliding galactic pair consists of a Seyfert 2 nucleus to the southwest and a LINER nucleus (low ionization nuclear emission-line region) to the northeast. The system is also classified as a LIRG (Luminous Infrared Galaxy) and has been well studied in X-ray, radio and infrared wavelengths, with 304 references in NED (Nasa-IPAC Extragalactic Database).

NGC 5144.jpg
NGC 5144
13 22 54.2 +70° 30’ 52"
V = 13.1; Size 1.2'x0.9'; Surf Br = 13.0; PA = 150°

This appears to be another post-merger system with two nuclei. It could be a single disrupted system -- but there's no obvious nearby galaxy that could have caused the damage. The general glow of NGC 5144 is moderately bright, irregularly round, fairly small, 0.7'x0.6', mottled or uneven surface brightness but no distinct core. Situated at the midpoint of a mag 11.8 star 1.9' NNW and a mag 13.7 2.0' SSW.

NGC 5144 probably has a merged companion at the south edge, catalogued as NGC 5144 NED01 as well as as LEDA 200298. It appeared as a quasi-stellar knot (less than 6" diameter) at the south edge of the halo, just 18" from the center of the main galaxy!

[Ivan Maly]

Also this spring, I observed NGC 5256. Though aware of its double nature I made no special effort to resolve it, staying at the "survey" power of ~200 in the 20", and described it simply as "round", noting also the double star. SQM 21.43. Great catch of the companion, Steve.