Some Arp Peculiar Galaxies with 8-inch Telescope

Devoting some time from my usual asteroid work to image some galaxies in honour of the late great astronomer Halton Arp. These are examples from some of the brighter galaxies from his “Atlas of Peculiar Galaxies” that Cherryvalley Observatory could image within its capabilities using an 8-inch SCT.

flic.kr/s/aHsjpwCNrR

Best wishes and clear skies
Mike

I believe Arp only passed away recently. I remember he gave a talk at the Whirlpool Star Party (Birr) about 10 years ago. A controversial astronomer who was 40 years ahead of his time.

Beautiful images Mike. Its amazing the detail you've got with an 8 inch telescope. The detail is important in understanding these galaxies as regards the red shift hypothesis.

It would be a good exercise to image some of these galaxies to see visually this peculiarity. Telescopes 12 inches plus CCD would bring out more detail. I'm sure there are a few members with medium size telescopes that could image them.

BTW, does the Arp galaxies have NGC numbers/Messier numbers, if one wanted to image some of them?

Eamonn

Hi Eamonn, thanks for your comments.

Dr. Arp passed away in December last year, so perhaps a fitting time that Cherryvalley Observatory had an opportunity (and the rarity of some clear weather) to image some of the brighter galaxies from Dr. Arp’s Atlas of Peculiar Galaxies. It’s proved to be an interesting endeavour in finding out more about Dr. Arps research, looking forward to imaging more across the seasons of next year.

Arp number objects do indeed have associated IC, NGC, PGC and Messier designations, therefore relatively easy to find on sky atlases / planetarium programs.
An Arp numbered object will sometimes include a number of other designated objects. As an example take Arp number object 331, an example of a distinct chain of galaxies, associated with the Pisces cloud or group as it is sometimes known, this would include NGC and PGC listed galaxies.
Cherryvalley Observatory uses TheSky6 Professional planetarium program, I imported a handy script listing all the Arp objects (338 of them), these then show up as highlighted Arp numbers which enables them to be easily found, I just click on an Arp number object and the telescope will slew to it. Image processing is then completed using CCDSoft and Mira-Pro to try and tease out subtle details.

Certainly many amateur astronomers in Ireland have access to larger and better equipment whom could image such Arp objects in more detail and indeed image the fainter Arp objects as well. As a suggestion I would like to propose the “Halton Arp Objects Challenge” through IFAS, similar to those that are established such as the popular binocular and Messier challenge.

Best wishes and clear skies
Mike

Are all the 338 Arp objects in the Northern Hemisphere? Are there some quasars designated as Arp objects because of the disputed redshift.
Its a nice idea doing “Halton Arp Objects Challenge” (HAOC)? What are the faintest ones if one is to observe all within the “HAOC". For example for visual observing and CCD capture. I realise it depends on telescope aperture.

Eamonn


Eamonn

Hi Mike

I will order a T-ring today and see if I can capture some on my DSLR. What's that software which is plotting what looks like the intensity?

Kevin

Mike said: I imported a handy script listing all the Arp objects (338 of them), these then show up as highlighted Arp numbers which enables them to be easily found,

Is that a private script or is it available somewhere. I'd love to have such a project to work on.