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Observing
Deep-Sky Objects
To locate constellations, stars or other deep-sky objects, it makes sense to use a star chart. We will list a selection of
deep sky objects here:
Stars are giant objects that mainly consist of gas. Due to the nuclear fusion in their core they radiate energy and
shine. The stars are extremely far away. Because of this vast distance they appear as tiny spots of light in your
telescope, despite their size – no matter how big your telescope is.
Nebulae are giant interstellar clouds of gas and dust. Within those clouds new stars are being born. The premier
nebula on the northern hemisphere is the Great Orion Nebula, a diffuse nebula that looks like a fuzzy patch of light
in the sword that branches off of Orion’s Belt. Also known as M42, it contains many intriguing features that pop to
life in a telescope.
An open cluster is a group of young stars that were born in a single diffuse nebula not too long ago (on an
astronomical time scale). The Pleiades is an open cluster that is relatively young, having formed within the last 100
million years, and lies relatively close to Earth at about 440 light years away. Found in the Taurus constellation, it
consists of more than 1,000 visual stars, although an average of only six are visible to the naked eye. A dark sky free
of light pollution can help a dedicated observer see around a dozen Pleiades stars, but your telescope will quickly
reveal many more of the elusive members of this legendary cluster.
Constellations are big patterns of stars that were believed to be celestial representations of men, gods and
objects by old civilizations. Those patterns are too big to be observed at a single glance through a telescope. If
you want to become familiar with the constellations, start with a pattern that is easy to find, like the Big Dipper in
the constellation Ursa Major. Try to locate the other constellations in the neighborhood of this constellation in the
second step and move on to other patterns.
Galaxies are gigantic accumulations of stars, nebulae and clusters that are held together by gravity. Most galaxies
have a spiral shape (like for example our own Milky Way galaxy), but there are also galaxies with elliptical or
irregular shapes. The closest spiral galaxy is the Andromeda Galaxy (M31). The core of M31 looks like a bright
patch of light in your telescope – under dark clear skies you will be able to detect features in this object with your
telescope.
