Posting images of galaxies in Halton Arp's Atlas of Peculiar Galaxies (1966).
Automated account. Image curation, descriptions, typos, and most alt text by human astronomer @KellyLepo.
See posts for image credits and links to the original sources.
Hubble Space Telescope image of Arp 4.
This image contains two galaxies, a larger irregular galaxy, Arp 4, and a small spiral galaxy PGC 6629.
Credit: NASA, ESA, STScI, Julianne Dalcanton, Meli thev, Wikimedia Commons
Source: https://commons.wikimedia.org/wiki/File:Arp_4_Hubble.jpg
Hubble and Pan-STARRS image of Arp 300, also known as UGC 05028 and UGC 05029.
UGC 05028 (the smaller spiral galaxy) and UGC 05029 (the larger spiral) form an interacting pair.
In this image, the luminosity comes from Hubble ACS/WFC observations, and color comes from PanSTARRS.
Credit: NASA, ESA, STScI, J. Dalcanton, Judy Schmidt, PanSTARRS
Source: https://www.flickr.com/photos/geckzilla/47129821172/
Hubble image of Arp 195, also known as UGC 4653.
This image of three interacting galaxies is from the Establishing HST's Low Redshift Archive of Interacting Systems snapshot program. These programs fill in gaps in Hubble's schedule (2-3 percent of the available time) with short observations.
In this image, the luminosity is from Hubble ACS/WFC observations, and color is from DECam and SDSS.
Credit: ESA, NASA, J. Dalcanton
Source: https://esahubble.org/images/potw2130a/
Hubble image of Arp 91, also known as NGC 5953 and NGC 5954.
NGC 5953, the large galaxy at center, and its companion NGC 5954 in the upper right show clear signs of gravitational interaction. A spiral arm or tidal tail from NGC 5954 extends downward and connects to NGC 5953.
Credit: ESA, NASA, J. Dalcanton, J. Schmidt
Source: https://esahubble.org/images/potw2140a/
Chandra, Hubble, and JWST image of Arp 220, also known as IC 4553.
Arp 220 is actually two spiral galaxies in the process of merging. In this composite view, the hottest gas, which glows in X-rays, is shown in purple, overlayed on a Hubble and JWST visible and infrared light view of the merging galaxies.
Credit: NASA, CXC, SAO, ESA, CSA, STScI, L. Frattare, J. Major
Source: https://chandra.harvard.edu/photo/2024/25th/more.html
Sloan Digital Sky Survey image of Arp 1, also known as NGC 2857.
NGC 2857 is a spiral galaxy in the constellation Ursa Major.
Credit: SDSS
Source: https://commons.wikimedia.org/wiki/File:NGC2857_-_SDSS_DR14.jpg
Image of Arp 285, also known as NGC 2854 and NGC 2856, from the Atlas of Peculiar Galaxies by Halton Arp (1966).
In the original catalog, it was in the category: Double and multiple galaxies - Infall and attraction. The lower galaxy, NGC 2856, has a clumpy tail perpendicular to its disk. It's an example of a “beads on a string” feature, where gravity creates knots of star formation at regular ~3,000 light year intervals.
Image of Arp 2, also known as UGC 10310, from the Atlas of Peculiar Galaxies by Halton Arp (1966).
In the original catalog, it was in the category: Spiral galaxies - Low surface brightness. Similar to the Large Magellanic Cloud, UGC 10310 is a barred Magellanic spiral galaxy.
Hubble image of Arp 283, also known as NGC 2798 and NGC 2799.
The left galaxy in this interacting pair, NGC 2799, is viewed edge-on. A bridge of star forming regions appears to connect it to its companion on the right, NGC 2798. NGC 2798 has two broad smooth spiral arms or tails without obvious clumps, made of mostly older, yellow stars.
Credit: ESA, NASA, J. Dalcanton, J. Schmidt
Source: https://www.flickr.com/photos/geckzilla/48172263957
Image of Arp 194, also known as UGC 6945, from the Atlas of Peculiar Galaxies by Halton Arp (1966).
In the original catalog, it was in the category: Amorphous galaxies - Material ejected from nuclei. This interacting galaxy group includes a pair of merging galaxies with trails of star clusters at top and a single large spiral galaxy at bottom. Together they form a question mark shape.
Hubble image of Arp 189, also known as NGC 4651.
While not visible in this image of the center of the spiral galaxy, NGC 4651 was included in the Arp catalog because of a narrow stellar stream in its outskirts. The stream is the remnants of a small galaxy that was ripped apart as it fell into the halo of the large spiral.
Credit: ESA, NASA, D. Leonard
Source: https://esahubble.org/images/potw2013a/