The Moon and the planets orbitting our Sun are extraordinary sights viewed with magnification
through simple binoculars or telescopes. Beyond these magnificent sights are some truly magical objects that could have been conjured up in dreams or by fantasty authors, yet
actually exist. These are Deep Sky Objects. They can sometimes be seen in binoculars but are generally better resolved (seen clearer) as the size of the obseving
telescope increases.
Generally speaking a deep sky object is anything that appears in the sky, which isnīt a planet or the Sun
within our Solar System. The Hubble Space Telescope (HST) and some of the lesser-known such as the Spitzer Infrared telescope have taken some wondrous images of deepspace objects
that might only appear as a smudge to the naked eye. Deep sky objects are classified under several categories.
Categories of Deep Sky Objects
Open Star Clusters are loose groups of numerous stars.
Globular Clusters are larger groupings of stars drawn together into more concentrated spherical shapes.
Diffuse Nebulae are clouds of glowing gas and dust.
Dark Nebulae are clouds of gas and dust that hide the stars behind them.
Planetary Nebulae have nothing to do with planets but are formed when a star reaches middle age, swells to many times their original size and puffs
out layers of gas into space which glows around the hot star at the centre.
Supernova Remnants are caused when a star explodes as a supernova and leaves behind an expanding cloud of glowing gas. On average,
supernovae occur about once every 50 years in a galaxy the size of the Milky Way.
Galaxies have different shapes and are composed of trillions of stars, clusters and nebulae of their own.
Galaxy Groups are clusters of galaxies.
Quasars are extremely bright centres of apparently otherwise normal galaxies.
Messier Objects
One classification of Deep Sky Objects is denoted by a prefix of īMī after the French astronomer Charles Messier who first catalogued them in the 18th century. These
objects were accessible using Messierīs relatively small 4 aperture telescope, and appear spectacular using modern day technology.
INTERACTIVE MESSIER CHART
Click on a thumbnail image below to link to full details
Amateur astronomers
compete to view all the objects from M1 (the Crab Nebula) through to M110 (a galaxy near Andromeda) in a single night from dusk to dawn. As Messier
compiled his catalogue from a northern latitude, not all of the objects are visible in the southern hemisphere. The best conditions for completing a Messier
marathon are at a latitude of 25š north, from mid-March to early April, at the time of a new Moon when interference from the Moonīs light is minimal. The
objects should be viewed in a certain order, starting with those low in the western sky at sunset before they set out of sight below the horizon, then
working eastwards across the sky. By sunrise the last few objects are seen before the sky becomes too bright.
Messier Objects: