Welcome to my Arp site. On this site, you'll find images of all 338 Arp Peculiar Galaxies, acquired with modest amateur equipment. The largest telescope used was a 10-inch Newtonian. For a preview of a few of the images, click on Quick Tour at the left. You can use the Previous and Next buttons on each page to step through them. The images on Quick Tour are the same as those on the regular image pages except that they are larger, show positives only, and don't include any descriptive text.  If you don't see an Index frame to the left of this page, click on this link

The Arp Atlas of Peculiar Galaxies

The Arp Atlas of Peculiar Galaxies was first published in the Astrophysical Journal Supplement Number 123, Volume 14, November 1966, University of Chicago Press, by Dr. Halton C. Arp.  Later it was republished as a separate atlas.  For an excellent history of Dr. Arp's career and the Atlas, and for extensive information on the fields, such as positions, magnitudes, sizes, alternate (and corrected) catalog designations, and names of other field galaxies, I strongly recommend Kanipe and Webb, The Arp Atlas of Peculiar Galaxies, A Chronicle and Observer's Guide. See Links. Their book is the definitive reference for the Arp galaxies. 

Dr. Arp's images are of fields, not necessarily of individual galaxies. While some Arps are single, most are pairs, groups, or entire galaxy clusters. And, because my field sizes are almost always much larger than Dr. Arp's, you will find far more than 338 galaxies on this site.

The images on this page are immediately recognizable as M51, but they are also included in the Atlas as Arp 85.  A number of Messier objects were included when they met Dr. Arp's definition of peculiar.  M51 fits into his classification of Spiral Galaxies with Large, High Surface Companions on Arms.  That shows up clearly on the positive and negative images but, to me, the most peculiar aspects of this pair are the "three fingers and thumb" on the north (top) side and the faint arm or bubble to the east (left).  These show best on the false color image to the left.

Navigating the Site

You will use the Index frame at the left for almost all navigation. It provides links to all the other pages. You are on Home and already know about Quick Tour. The contents of Equipment, Processing, About Me, Thanks and Links should be obvious. The Project contains the history of this effort, some observations on the process, and a few statistics.  Image Pages is not the link to the images themselves. Instead, it describes orientation, scale, the various ways the images are presented, and the type of information that will be found in the text.  I suggest you view this page before visiting the images themselves.  Updates is a list of all corrections, additions, improved images, etc., by date so you can see what may have changed since your last visit.  The number range links, for example, 1-18, are the paths to the images. Each range link will take you to a page of thumbnails, and the thumbnails link to the images. From an image page, you can browse with the Previous and Next buttons, use your browser's Back button to return to the thumbnails, click a link to go directly to the matching Atlas image, or just go back to the Index.  All external links (like the Atlas images) open a new page.  When you are ready to return to this site, just close it.

The site is optimized for 1024 x 768, or higher, resolution.  If your resolution is lower, you will need to do more scrolling and some of the page layouts will look strange.  If your browser allows it and your monitor is at least 1024 x 768, you might try the Full Screen mode.  Because the site is "image intense", a high-speed connection will make the viewing experience much more enjoyable.  The average page takes about 15 seconds to load using 56K dial-up.  Also, I've found some monitors don't show the images well, or need adjustment.  If you see any colors in the images other than pure grayscale (brownish, purplish, etc.) or if faint details mentioned in the text aren't visible, try adjusting the monitor.  The available adjustments vary so much that I can't give you much advice.  You can use the first image on Quick Tour as a test.  So far, all LCD monitors I've tried have worked well but there has been a lot of variation in CRT monitors.  Some work great, some can be adjusted to give good images, but others, particularly older ones, won't work well no matter what you do.