Kiwanis Chico Community Observatory







Message Group

Deep Sky Objects

Students for the Exploration and Development of Space (SEDS)


    Deep sky objects "live" outside of our solar system.  They consist of various celestial bodies including:



globular cluster - a spherically symmetric, highly condensed cluster of stars, containing tens of thousands to a million members*


open cluster - a group of a few ten to a few thousand stars that formed together in the disk of a spiral galaxy (also called galactic clusters)*


galaxy - a gravitationally bound system that consists of stars and star clusters, gas, dust, and dark matter; typically greater than 1,000 lightyears across; and recognizable as a discrete, single object*


nebula - latin word for "cloud"


    There are a few different places where deep sky objects are catalogued.  The first of these was developed by Charles Messier in the 18th century.  SEDS (students for the exploration and development of space) has a wonderful website explaining the history of the Messier catalogue.  They also talk about the individual deep sky objects classified in this catalogue.  For more information on the Messier catalogue, please visit


    The two other main catalogues are NGC (new general catalogue) and IC (index catalogue).  These catalogues were put together more recently, in the late 19th century.  They are also more extensive than the Messier catalogue, each having a few thousand objects, compared to Messier's 110 objects.


    At the Chico Community Observatory, we tend to show mostly Messier objects, since they are generally larger and brighter than NGC or IC objects.  We are always happy to observe one of the latter types if someone is interested.



*21st Century Astronomy (Hester, Burstein, Blumenthal, Greeley, Smith, Voss, and Wegner)


For more information on deep sky objects, please visit SEDS' website at


Our Sun

Our Moon

Solar System

Deep Sky Objects




Website last updated March 16,  2006.  Hosted by Anthony Watts, KMXI Radio.  Webmasters Tiara Norris and Brendan Diamond.