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Deep-Sky Gems

About the Deep-Sky Gems List

During a lifetime of comet hunting David Levy has swept up many unique and interesting deep-sky objects and through this certificate he shares with us the best 154 of his Deep Sky Objects (Prometheus Books, New York 2005). Leo Enright is credited with planting the seed from which this certificate has grown and invested a great deal of time on the project.

Many deep-sky objects in the list are from the NGC and IC but it also contains unique objects, such as Levy 384, Tombaugh’s Cluster, and a dust field. The Deep-Sky Gems list was first published in the RASC Observer's Handbook in 2008. The application forms can be found from a link at the bottom of this page.

Below is an overview of the Deep-Sky Gems observing list:

GEM Objects Number Notes
Open Clusters 14 Including the overlooked naked-eye open cluster NGC 752, Tombaugh’s Cluster, and the Christmas Tree Cluster in Monoceros.
Globular Clusters 14 “Intergalactic Wanderer” in Lynx and Globular cluster in NGC 7006 in Delphinus.
Bright Nebulae 7 Unusual objects such as NGC 1333, the Embryo Nebula, and NGC 7023, The Iris Nebula, along with other “weird” nebulae. Some are associated with nearby star clusters.
Planetary Nebulae 1 Their size and brightness make an interesting comparison.
Galaxies 112 Large and small, round and elongated, there is a great variety of galaxies, spiral, elliptical, and unusual.
Double Quasar 1 This is the remarkable double quasar known to act as a gravitational lens +561A/B in Ursa Major
Nebula-Dust-Field 1 NGC 2174 known as the Monkey Head Nebula
Galaxy Clusters 3

IC and Arp clusters visible in medium sized scopes.

Asterism 1 This is a very special asterism that has gained recognition in observational literature as "Levy 384" in Puppis
Total 154  

NOTE: A revision has been made to remove duplicates that exist in other RASC Certificate Programs and the update will appear in future editions of the Observers Handbook. Two objects exist in our Finest NGC Certificate Program as well as two from the Deep-Sky Challenge Certificate Program. Replacement objects were selected from candidates obtained after reviewing David's original Deep-Sky Objects list, in consultation with Dr. Levy and Mr. Enright's work.


List of duplicates as printed in 2012:

Levy # Object R.A. (2000) Dec. Mag. Size (') U UDSA Notes
L1 NGC 1931 05 31.4 +34 15 13.0 4 × 4  97 59 A “Finest” condensed nebula in Auriga
L245 NGC 6781 19 18.4 +06 33 11.4 >1.8 206 85 Planetary nebula in Aquila
L325 IC 1795 02 26.5 +62 04   40 × 15 17 17 Bright nebula in Cassiopeia
L381 U 5470 10 08.5 +12 18 10.2 12.0 × 9.3 189 92 Dwarf elliptical galaxy in Leo

Replace with:

Levy # Object R.A. (2000) Dec. Mag. Size (') Notes
L279 NGC 6522,
NGC 6528
18 03.6 -30 02 8.3 16.4 Baade's Window; two faint globular clusters close to Galactic Centre  - Sagittarius
L120 NGC 6451 17 50.7 -30 13 8.2 7 Note: "Tom Thumb Cluster" Small Scorpius Open Cluster; Galactic Centre - Scorpius
L324 Tombaugh 5 03 47.8 +59 03 8.4 14 Note: Open Cluster - Camelopardalis
L140 NGC 4485 12 30.5 +41.42 11.9 2 x 1.3 Elongated Galaxy, just N of NGC 4490 Cocoon Galaxy - Canes Venatici

The RASC's Deep-Sky Gems Certificate

The Deep-Sky Gems is an excellent project for those who have completed their Messier and NGC Certificates and are looking for another visual observing program. The official list can be found in the RASC Observer's Handbook. At least a 20-cm (8-inch) telescope is recommended for tackling the list, but an instrument with an aperture in the 40-cm (16-inch) range will be needed to satisfactorily observe the quasar. A nebular filter will assist in observing most of the nebulae. Several Deep-Sky Gems may be observed in smaller instruments or without optical aid, so that virtually anyone can begin this project without a trip to the scope shop. Nebular filters will assist in the observation of faint glowing clouds of gas, but note that reflection nebula to not benefit from such filtration.

The Deep-Sky Gems 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 Deep-Sky Gems Certificate program:

  • Deep Sky Objects - by David H Levy, The Best and Brightest from Four Decades of Comet Chasing.

  • Sky Atlas 2000 - by Will Tirion is an excellent sky chart set that contains all of the objects on the Finest NGC list.

  • The Night Sky Observer's Guide - by George Robert Kepple and Glen W. Sanner contains descriptions and finder charts for most of the objects on the Finest NGC list.

Deep-Sky Gems Tradtional Application Form239.68 KB
Deep-Sky Gems Computer-Aided Application Form243.31 KB