Arp Peculiar Galaxy (Southern) Observing Program

Arp Peculiar Galaxy (Southern) Observing Program Coordinator::

Marie Lott
2836 Rangewood Ter NE
Atlanta GA 30345-1581
(404) 941-5688



Galactic evolution may include interaction and disturbances between and among galaxies. The changes occurring are in slow motion by our time standards so when we view galaxies, we are witnessing a mere snapshot of the evolutionary process. Halton Arp documented 338 peculiar galaxies in his article Atlas of Peculiar Galaxies1 in 1966 and more recently Kanipe & Webb2 published a book with many images of peculiar galaxies.

Twenty years later Halton Arp and Barry Madore published a catalogue of southern peculiar galaxies3. This was done for several reasons: to document a larger sample of peculiar galaxies to investigate the nature of their redshifts and “to survey systematically the rich forms found among galaxies, from which new insights and, at the very least, a close familiarity would arise.”3

Background Information

Purpose & Significance:

The purpose of this Observing Program is to provide an auxiliary and unique challenge for visual and imaging observers of the Arp Peculiar galaxies. It complements and extends the existing Arp Peculiar Galaxy Observing Program (Northern Arp) of the Astronomical League by providing additional peculiar Arp galaxies in the Southern celestial hemisphere. The objective is to provide additional observing material for any observer in the Northern or Southern hemisphere. This new addition is based on 498 objects selected from the catalogue published by Arp et al.3,4. The galaxies selected are brighter than 15th magnitude, with many of them falling within the range of moderately-sized amateur telescopes under dark, transparent skies.

Requirements and Rules

This certification is available to members of the Astronomical League, either through their local astronomical society or as members at large.  If you are not a member and would like to become one, check with your local astronomical society, search for a local society on the Astronomical League Website, or join as a Member-at-Large .

  • Observers from either the Northern or Southern hemisphere will be required to observe any 100 of the Southern Arp galaxies. There are 122 galaxies higher than -30o declination.
  • Observations will be telescopic and can be recorded either visually (V) or electronically/photographically (E).
  • The galaxies can be located manually (M) or with digital setting circles (D; this includes Go-To capabilities).
  • Visual observations, log sheets should contain:
    • Date and time.
    • Latitude and Longitude of observation.
    • Sky conditions: transparency, and seeing.
    • Telescope aperture and focal length.
    • Whether the object was found manually, with digital setting circles or a Go-To telescope.
    • Magnification
    • The Arp-Madore (AM) catalogue number of the Southern Arp galaxy observed.
    • Observing details and descriptions.
  • Photographic or digital imaging observations:
    • Include all of the requirements of Visual Observations.
    • If multiple galaxies are in the field, the Southern Arp galaxy should be indicated clearly.
    • Field of view.
    • In addition, log sheets should contain the type of camera used.



Assisting Al Lamperti in the development of this program were other members of the Delaware Valley Amateur Astronomers: John Bajtelsmit, Mark Huss, Vince Scheetz and Frank Colosimo, whose image of the galaxy is used on the certificate and pin. A special thanks to Barry Madore who advised how to navigate the NASA Extragalactic Database (which he helped develop) to retrieve the parameters of the Southern Arp galaxies needed.

Submitting for Certification

  • The log sheets with visual observations or digital images (which should be submitted on a CD-ROM or via URL if images are posted online) should be sent to the Southern Arp Observing Program Coordinator. The observations will be verified by the Observing Program Coordinator. Separate certificates will be issued for Visual and Imaging, and observers are encouraged to apply for both! If you have already received a pin and certificate for the Northern Arp, you will receive just a certificate for the Southern Arp, as only one pin is awarded.
  • Include your name, mailing address, email, phone number, and to whom the certification should be sent.

Upon verification of your submission and of your active membership in the Astronomical League, your recognition (certificate, pin, etc.) will be sent to you or to the awards coordinator for your society, as you specified.  Your name will also appear in an upcoming issue of the Reflector magazine and in the Astronomical League’s online database.  Congratulations.  Good luck with your next observing challenge.

Arp Peculiar Galaxy (Southern) Observing Program Coordinator::

Marie Lott
2836 Rangewood Ter NE
Atlanta GA 30345-1581



  • 1 Atlas of Peculiar Galaxies, Arp, H. Astrophysical Journal Supplement 14: 1-20, 1966
  • 2 The Arp Atlas of Peculiar Galaxies – A Chronicle and Observer’s Guide, Kanipe, J. and Webb, J. Willmann-Bell Publishers, 2007.
  • 3 A Catalogue of Southern Peculiar Galaxies and Associations, Arp, H. C. and Madore,  B.F., Vol. 1, Positions & Descriptions, Cambridge University Press, 1987.
  • 4 A Catalogue of Southern Peculiar Galaxies and Associations, Arp, H. C., Madore, B.F. and Roberton, W.E., Vol. 2, Selected Photographs, Cambridge University Press, 1987.
Scroll to top