Back to my favourite subject, the Arp peculiar galaxies.

Arp 239 is a pair of interacting spirals very similar to M51. Arp 239 consists of two galaxies, NGC 5278 and 5279. There is a common arm between the 2 galaxies and Arp notes that the "smaller galaxy is fairly symmetric spiral" and placed it in his 'Appearance of fission' group. A super nova was seen in the western galaxy in 2001.

It appears that the rotation of each galaxy is not actually centred on the core of each galaxy and this is probably a result of the interaction between the 2.

NGC 5278 is classed as SA(s)b? and red shift data puts the pair at around 350 million light-years distant. Apparent magnitude for ngc 5278 is 13.6, it is pretty small, about 50" x 40".

There are a lot of other galaxies in the image. Some of them are notated on the Astrobin image but some are incredibly distant at around 1.6 billion light years or more. There are 6 quasars within 25 ' from Arp 239 but sadly none are in my fov. But there are a lot of galaxies to the W of Arp 239. Such as IC 917 to IC 934. Most of them form the galaxy cluster Abell 1783 and this group is around 900 million light years distant. It has a diameter of 30 arcmin so a lot of it is out of my frame. The bright galaxy down and to the right of Arp 239 is UGC 8671, and the small spiral above UGC 8671 is MCG+9-22-94. Just to the right is the very distant galaxy SDSS J134115.89+554053.2 at 1.6 billion light-years.

However the rather bright elliptical IC 919 is not a part of Abell 1783. It is probably only around 500 MLy but the nearby edge-on spiral IC 918 is part of the Abell group. Things are not always as they look.

I enclose a link to Halton Arp's wonderful image taken through the 200" in the mid 60's. When you think this was taken on film and probably hand guided for hours at a time, you get a feel for the dedication to his task this man had.

My image a mere 90 minutes exposure, auto guided using a 10" reflector and a SX H9C camera.

Arp's image:

http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp239.jpeg