Deep-Sky Challenge

Deep-Sky Challenge Observing Program

About the DSC List

The DSC list, compiled by Alan Dyer and Alister Ling complements the FNGC list, as there is no overlap. The list features "fringe" deep-sky treasures that are somewhat more challenging objects than what most observers look for. The attraction of observing is not the sight of an object itself but the intellectual contact with what it is. The DSC certificate has been awarded since 2008. Prior to this, a letter of achievement was given out by the Observing Committee to anyone who had completed the DSC list. Those who have received this have been awarded the certificate in 2008. An application form can be found from a link at the bottom of this page.

Here is an overview of the DSC Observing List:

Deep-Sky Challenge Objects Number Notes
Open Clusters   2 NGC 609 in Cassiopeia and NGC 6791 in Lyra.
Globular Clusters   4 Includes Palomar 11 in Aquila.
Emission/Reflection Nebulae   13 Includes California Nebula in Perseus and Barnard's Loop in Orion.
Dark  Nebulae   2 Includes B33, the Horsehead, and B72, the Snake.
Planetary Nebulae   8 Includes Jones 1 in Pegasus.
Supernova Remnants   1  
Galaxies / Galaxy Clusters / Quasars   15  
Total 45  


The RASC's DSC Certificate

The DSC list is an excellent project for those who have completed their FNGC or Messier Certificate and who are looking for a challenging observing program. The official list can be found in the RASC Observer's Handbook. At least a 30-cm (12-inch) telescope is recommended to complete most of the list, although it can be done with a 25-cm (10-inch) under good skies. A few of the objects will require access to a large telescope (50-cm / 20-inch). Several DSC objects can be observed in even smaller instruments, so these could be used to get started on the brighter objects. With all instruments, a nebular filter will be necessary to see the often visually faint glowing clouds of gas and dust of some objects.

The DSC certificate can be started during any season. You must be a member in good standing of the RASC to be awarded this certificate.


Here are some recommended resources to help you tackle the DSC Certificate program:

  • Uranometria - by Wil Tiron is adequate for most objects
  • Tri-Atlas - by Jose Torres and Casey Skelton, free downloadable PDF charts contain all objects.
  • Earth Centered Universe - by Dave Lane — useful PC Software.
  • The Night Sky Observer's Guide (Volumes One and Two) - by George Robert Kepple and Glen W. Sanner, contains descriptions and finder charts for many of the objects on the challenge list.
PDF icon Deep-Sky Challenge Form 2016 (PDF)227.91 KB
Last modified: 
Monday, September 5, 2016 - 8:44am