M42     The Great Nebula in Orion (NGC 1976)

        Object type:             Emission (H II region) nebula

        Distance from Earth:      1600 light years / 490 parsecs

        Distance across Nebula:   16 light years / 4.9 parsecs


        The Orion Nebula is the middle 'star' in the sword of Orion the
        Hunter.  M42 can be seen without optical aid as a hazy star, but
        through even a small telescope it is a magnificent sight.  M42 is the
        brightest nebula visible from Earth and is thus the best studied.
        Its distance is 1600 ly - relatively close.  Many new stars are
        forming in the interior of the cloud and several proto-solar systems
        have been discovered with infrared astrophotography.  Six inch and
        larger telescopes reveal a cluster of four stars at the heart of the
        nebula called the Trapezium (the stars form the corners of a regular
        trapezoid).  These stars are among the youngest yet discovered.
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