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.

Hi Eamonn
There is indeed Southern Arp Objects with associations. This work came some time later and is perhaps better known as the Arp-Madore Catalogue, AM for short as these objects are listed as AM ****-*** from that survey. I believe it was published in the late 80’s in two volumes. See link for additional information…
ned.ipac.caltech.edu/level5/SPGA_Atlas/frames.html
Regarding quasars associated with relatively nearby galaxies from the Arp atlas it’s proven to be very interesting time indeed. The basic theory as best I can explain it goes something like this; Quasars are not the most distant objects in the universe but are associated in space with relatively nearby galaxies and therefore quasars astounding redshift values are not linked to the accelerating expansion of the universe but display intrinsic properties which are part and parcel to the quasar itself and thus independent. Quasars associated with galaxies appear to undergo an ejection process in lines or chains from the host galaxy’s center, Arp (and others) have found through statistical analysis and observations that the odds of such quantities of quasars appearing this way and associated with nearby galaxies is far beyond chance. Connected with these ejection chains of quasars from host galaxies are associated ejected radio material and x-ray material sources. This of course calls into question not only our basic understanding of galaxy formation, evolution and morphologies but also undermines how we think the universe is as opposed to how it perhaps actually is. In my opinion we simply need more astronomers like Halton Arp to push the boundaries and make us think more deeply, a sad loss indeed.

Hi Kevin,
It would be interesting to view your imaging efforts with a DLSR when completed.
The software is Mira-Pro v7 (2007). See link below for updated software. A short description I lifted from the website;
“Designed for critical astronomical applications, Mira® Pro Ultimate Edition™ includes research-level image calibration, data reduction, visualization, and measurement tools, plus a powerful programming extension language for scripting, algorithm development, simulation, and other computational needs”. Unfortunately it doesn’t come cheap but there are student versions which are cheaper.

www.mirametrics.com/mira_pro_ue.htm

Hi Kinch
The file was available from Software Bisque’s (Tom’s Corner) website. It was designed for their own “TheSky6” planetarium software which could then be imported easily into TheSky6 database. If you have trouble finding it online I can send it to you by email.

Best wishes and clear skies
Mike

Thanks Mike.
When I went searching I found that I had it in SkyX SAE as an additional database.

I was surprised that some of the Arp galaxies were bright. I took some images of three of them. You could even use a 4 inch telescope. I can send them on to you Mike for your evaluation. It won't be soon as I'm in the USA at present, so when I come back in mid January I'll send them on to you.

BTW, regarding your observational work on asteroids. I'm in the middle of reading Roger Dymock's book
"Asteroids and Dwarf Planets". Thanks for your recommendation of this book. I would recommend it to any budding observer who wants to know how to do hands on practical observing and make a contribution to astronomy.

Eamonn

Hi Eamonn

Yes, some of the Arp objects are relatively bright and within the imaging capabilities of many amateur astronomers. I look forward to seeing the results of your Arp images from a much larger aperture telescope.

I agree Eamonn, Roger Dymock’s book is a fantastic resource to have! It helped enormously in not only sparking this amateur astronomer’s interest in asteroids but also providing clear information on the practicalities of how to obtain an observatory code and undertaking asteroid photometry.
I can also highly recommend Brian Warner’s book “A Practical Guide to Lightcurve Photometry and Analysis”.

Best wishes and clear skies
Mike

Might be useful for anyone who does not have the catalogue database add on - a list of Northern ARP Objects by location, constellation etc.

www.astroleague.org/al/obsclubs/arppec/arppeca.html

I have also added a spreadsheet I use and I have filtered it by ARP objects. ( Edit: I can't upload the file even though it says you can upload zip files)

Here is the URL

Here is the URL www.astronomyclub.org/obs/whatsup/f_wud.htm

Given the terrible weather of late I took an opportune observing session a few days ago to chase some Arp Galaxies to add to the list.
flic.kr/s/aHsjpwCNrR

Mike

Cherryvalley Observatory (I83)
Co. Meath.

I was just looking through those a few minutes ago - lots of work gone into all of those shots. Thanks for posting.

Fantastic set of images Mike. Love the presentation too.