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Astr112 Photography Projects, Spring 2006

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M99 Pinwheel Galaxy, Kyle Schultz


Discovered by Pierre Méchain0 in 1781, M99 is a bright galaxy about 73,300 light years wide, located in a cluster of galaxies referred to as the Virgo Cluster. It is of the Sc type of galaxies, meaning it has a less pronounced bulge and loosely wound spiral arms. Also, M99 is located about 60 million light-years away from Earth in the constellation Coma Berenices.

M99 has a normal looking arm and an extended arm on the right portion of this photograph which arches out more than usual. A bridge of neutral hydrogen gas links this nebula to a dark matter halo, otherwise known as a dark galaxy. This is believed to be the cause of distortion in the shape of M99 and it is expected to conform to standard shaping after it is out of the effectual gravitational field of the dark galaxy.



Right Ascension (J2000) 12h 18m 49.3s
Declination (J2000) +14°25'07"
Filters used clear(C)
Exposure time per filter 4 x 60 seconds in C
Date observed

March 3, 2006 (C)