A R P     P e c u l i a r     G a l a x i e s



            created: 09-10-2014.             revised: 09-01-2017.

Hello!

per Wikipedia: Interacting galaxies (colliding galaxies) are galaxies whose gravitational fields result in a disturbance of one another. An example of a minor interaction is a satellite galaxy's disturbing the primary galaxy's spiral arms. The satellite's gravity could attract one of the primary's spiral arms. Or the satellite could dive in to the primary, disrupting it.
An example of a major interaction is a galactic collision of two large galaxies. Because of the tenuous distribution of matter in most galaxies, these collisions are not like a head-on car wreak, but more of a gravitational interaction.


American astrophysicist Halton Arp, (1927 - 2013), graduated from Harvard University in 1949 and received his doctorate from Caltech in 1953. In 1957, he became a staff member at Palomar Observatory, and worked there for 29 years. Later, In 1983 he went on to join the staff of the Max Planck Institute for Astrophysics near Munich, Germany.
While at Caltech, he began 'collecting' unusual galaxies that other researchers would drop from their studies as being too unusual or peculiar. Arp realized that these odd galaxies represented different stages in galaxy evolution, and devoted his career to studying them and related quasi-stellar objects (QSOs), utilizing the 200-inch Hale telescope.
This eventually led to his challenging the current interpretation of some of these highly redshifted sources, even calling into question the Big Bang theory. Until his death in 2013, Arp continued to hold his contrary view and published his research in both popular and scientific literature. Today, with modern observatory cameras and space telescopes available, conclusive research has proven Arp's "counter-theories" of intrinsic redshift to be incorrect. But, even though he was eventually proven to be wrong, Halton Arp made significant contributions to astrophysics by his strong challenges to accepted theory, forcing other astronomers to re-validate their assumptions about galaxy formation and cosmology.
Arp's atlas also has become a useful tool for the advanced amateur astronomer looking for deep-sky observing/imaging projects.
The amateur astronomer will find many of the 'Arp' objects listed on star atlas's and observing guides as NGC, IC, and UGC galaxies.

         

Arp compiled a catalog of unusual galaxies titled Atlas of Peculiar Galaxies, which was first published in 1966 which contained photographs of 338 nearby galaxies that did not fall into any of the classic categories of galaxy shapes. Arp's atlas is recognized now as an excellent compilation of interacting and merging galaxies.

In 2006 Amatuer Astronomers Jeff Kanipe and Dennis Webb expanded Arp's atlas into an observers guide, complete with Arp's original images, along with finder charts and CCD images and visual observations from other participating amateurs.
It's a great book to use in the field!!



Additionally, there's several great online resources.
Amateur astronomer Bob Hill of the Amarillo Astronomy Club, has put together a great site of his observations on the 100 best Arp Galaxies by season. You can find the first installment here: Touring the Peculiar Universe:

Scottish amateur David Richards has a very good site of the ARP's visible from his home observatory: David's Astronomy Pages - ARP Peculiar Galaxies:

Also, amateur Alvin Huey has a good observing book on his website that you can purchase.
(he also has a number of free downloads too!) faintfuzzies:

Finally, you can find a PDF of Dr. Halton Arp's atlas online here at: ATLAS OF PECULIAR GALAXIES:

Below is my personal observation list of the 'Arp Atlas of Peculiar Galaxies'.

I currently have 67 out of a possible 337 objects visible from my Pittsburgh, PA latitude of around +40.
All of my images were taken using a StellaCam-3 peltier-cooled deepsky video camera. Each image has minimal processing applied to it: brightness/contrast adjusted, image rotated to match that of the Arp Atlas book, and resized to have the same general field size across images. I then made a negative 'finder chart' with a red line indicating the general location of the peculiarity.



Arp Peculiar Galaxies:

Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
2 UGC10310 Spiral:
Low Surface Brightness
Hercules 06/03/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
4 MCG-2-5-50 Spiral:
Low Surface Brightness
Cetus 09/01/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
8 NGC497 Spiral:
Split Arm
Cetus 09/01/2016 8" SCT f6.3 & Stellacam-3 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
13 NGC7448 Spiral:
detached segments
Pegasus 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
14 NGC7314 Spiral:
Detached Segments
Piscis Austrinus 09/19/2014 8" SCT f10 & Stellacam-3 with .5x reducer 55 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
19 NGC145 Spiral:
Three-Armed
Cetus 09/02/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
26 NGC5457 (M101) Spiral:
one heavy arm
Ursa Major 05/31/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
28 NGC7678 Spiral:
one heavy arm
Pegasus 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
29 NGC6946 Spiral:
one heavy arm
Cepheus 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
30 NGC6365A & B Spiral:
one heavy arm
Draco 08/06/2016 8" SCT f6.3 & Stellacam-3 180 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
31 IC167 Spiral:
Integral Sign
Pisces 09/26/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
32 UGC10770 Spiral:
Integral Sign
Draco 08/06/2016 8" SCT f6.3 & Stellacam-3 180 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
38 NGC6412 Spiral:
Low SB companion on arm
Draco 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
42 NGC5829 & IC4526 Spiral:
Low SB companion on arm
Bootes 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
51 MGC-2-1-24 Spiral:
small High SB companion on arm
Cetus 09/19/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
59 NGC341 Spiral:
small High SB companion on arm
Cetus 09/02/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
65 NGC91 & 93 Spiral:
small High SB companion on arm
Andromeda 09/19/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
66 UGC10770 Spiral:
small High SB companion on arm
Draco 08/06/2016 8" SCT f6.3 & Stellacam-3 180 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
68 NGC7757 Spiral:
small High SB companion on arm
Pisces 09/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
72 NGC5994 & 5996 Spiral:
Small High SB companion on arm
Serpens 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
73 IC1222 Spiral:
Small High SB companion on arm
Hercules 06/03/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
74 UGC1626 Spiral:
Small High SB companion on arm
Andromeda 09/26/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
78 NGC770 & 772 Spiral:
Small High SB companion on arm
Aries 09/26/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
81 NGC6621 & 6622 Spiral:
large high SB companion on arm
Draco 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
84 NGC5394 & 5395 Spiral:
large High SB companion on arm
Canes Venatici 06/24/2017 8" SCT f6.3 & Stellacam-3 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
85 NGC5194-5195 (M51) Spiral:
large High SB companion on arm
Canes Venatici 05/31/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
86 NGC7752 & 7753 Spiral:
large High SB companion on arm
Pegasus 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
91 NGC5953 & 5954 Spiral:
Large High SB companion on arm
Serpens 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
92 NGC7603 Spiral:
ellipitical companion on arm
Pisces 09/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
93 NGC7284 & 7285 Spiral:
Elliptical Companion on Arm
Piscis Austrinus 09/19/2014 8" SCT f10 & Stellacam-3 with .5x reducer 55 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
99 NGC7547, 49, 50 Spiral:
elliptical companion on arm
Pegasus 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
101 UGC10164 & 10165 Spiral:
Elliptical companion on arm
Serpens 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
102 UGC10814 Elliptical:
Connected to Spirals
Hercules 06/03/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
112 NGC7805 & 7806 Elliptical:
Repelling Spiral Arms
Pegasus 09/19/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
113 NGC67, 67A, 68, 69, 70, 71, 72, 72A, & 74 Elliptical:
Close to and Perturbing Spirals
09/19/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
124 NGC6361 Elliptical:
Close to and Perturbing Spirals
Draco 08/06/2016 8" SCT f6.3 & Stellacam-3 180 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
127 NGC191 & IC1563 Elliptical:
Close to and Perturbing Spirals
Cetus 09/02/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
135 NGC1023 Elliptical:
with Nearby Fragments
Perseus 09/26/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
140 NGC274 & 275 Elliptical:
Material emanating from elliptical
Cetus 09/02/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
144 NGC7828 & 7829 Elliptical:
Material emanating from elliptical
Cetus 09/19/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
153 NGC5128
"Centaurus A"
Galaxies:
Distrubed with Interior Absorption
Centaurus 05/18/2017 8" SCT f6.3 & Stellacam-3 45 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
157 NGC520 Galaxies:
Distrubed with Interior Absorption
Cetus 09/02/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
166 NGC750 & 751 Galaxies:
Diffuse Filaments
Triangulum 09/26/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
169 NGC7236 & 7237 Galaxies:
Diffuse counter-tails
Pegasus 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
170 NGC7578A, B & C Galaxies:
Diffuse counter-tails
Pegasus 09/19/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
184 NGC1961 Narrow Filaments Camelopardalis 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
185 NGC6217 Spiral:
Narrow filaments
Ursa Minor 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
188 UGC10214 Spiral:
Narrow filaments
Draco 08/06/2016 8" SCT f6.3 & Stellacam-3 180 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
200 NGC1134 Spiral:
Material Ejected from Nucleus
Aries 09/26/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
210 NGC1569 Irregularities, Absorption, and Resolution Camelopardalis 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
212 NGC7625 Irregularities, Absorption, and Resolution Pegasus 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
213 IC356 Irregularities, Absorption, and Resolution Camelopardalis 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
216 NGC7679 & 7682 Galaxies:
Adjacent Loops
Pisces 09/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
222 NGC7727 Spiral:
Amorphous Spiral Arms
Pisces 09/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
223 NGC7585 Spiral:
Amorphous Spiral Arms
Pisces 09/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
226 NGC7252 Galaxies:
Amorphous Spiral arms
Piscis Austrinus 09/19/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
227 NGC470 & 474 Galaxies:
Concentric Ring
Cetus 09/02/2016 8" SCT f6.3 & Stellacam-3 120 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
235 NGC14 Galaxies:
Appearance of Fission
Pegasus 09/192014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
241 UGC9425 Galaxies:
Appearance of Fission
Bootes 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
246 NGC7837 & 7838 Galaxies:
Appearance of Fission
Pisces 09/26/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
278 NGC7253A & 7253B Galaxies:
Interacting double galaxies
Pegasus 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
282 NGC169 & IC1559 Galaxies:
Double galaxies with infall and attraction
Andromeda 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
293 NGC6285 & 6286 Galaxies:
Double galaxies with wind effects
Draco 08/06/2016 8" SCT f6.3 & Stellacam-3 180 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
295 MGC1-60-21 & 22 Galaxies:
Double galaxies with long filaments
Aquarius 09/26/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
297 NGC5752,53,54 & 55 Galaxies:
Double galaxies with long filaments
Bootes 08/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
298 NGC7469 & IC5283 Galaxies:
Double galaxies
Pegasus 09/26/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
314 MGC1-58-9 thru 11 Galaxies:
Galaxy Group
Aquarius xx/xx/2014 8" SCT f10 & Stellacam-3 with .5x reducer 50 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
319 NGC7317, 18A, 18B, 19, 20 (Stephan's Quintet) Galaxies:
Galaxy Group
Pegasus 08/24/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
325 MGC4-52-14 Galaxies:
Galaxy Chain
Aquarius 09/25/2014 8" SCT f10 & Stellacam-3 with .5x reducer 60 sec
      
                    


Arp Object NGC / IC    Peculiarity    Constellation Date Telescope & Camera Exposure
337 NGC3034 (M82) Galaxies:
Unique
Ursa Major 06/08/2013 6" RC f9 & Stellacam-3 with .5x reducer 60 sec
      
                    





Hope you enjoyed the visit. Come again soon!
Larry McHenry,   Pittsburgh, PA. USA

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