METROPOLITAN SKIES
By Dave Trapani
SkyRunner
S
ky
Conditions
Galaxies
Galaxies are large systems of stars and interstellar matter, typically containing several million to
some trillion stars.  Some masses are between several million and several trillion times that of
our Sun.  Some galaxies contain extensions of a few thousand to several hundred thousand light
years, typically separated by millions of light years.  They come in a variety of flavors: Spiral,
lenticular, elliptical and irregular. Besides simple stars, they typically contain various types of star
clusters and nebulae.

We live in a giant spiral galaxy, the Milky Way Galaxy, that measures 100,000 light years in
diameter, and has a mass of roughly a trillion solar masses. The nearest dwarf galaxies, satellites
of the Milky Way, are only a few 100,000 light years distant, while the nearest giant neighbor, the
Andromeda Galaxy, also a spiral, is about 2-3 million light years distant.
2007
M51- 2/10, 2007
NGC 4565- 4/11, 2007
2006
M51- 12/16, 2006
M31 - August 6, 2006
January 21, 2006
M51- May 27, 2006
M51 - March 4, 2006
The Leo Trio Galaxy
Cluster - March 29, 2006
2005
BACK
TO TOP
September 9, 2005
May 30, 2005
May 9, 2005
April 9, 2005
2004
July 6, 2004
November 15, 2004
© 2012 David A. Trapani
MetropolitanSkies.com
All Rights Reserved
M101 - 4/25/2007
M31 - 9/20/2007
M33 - 11/02/2007
NGC 891 - 11/13/2007
M104 - 4/24/2008
2008
M51 - 4/30/2008
M31 - 7/4/2008
M101 - 7/4/2008
M51 - 7/5/2008
M33 - 8/30/2008
M104 - 1/3/2009
2009
M51 - 4/23/2009
M31 - 8/26/2009
NGC 4565 - 4/2/2010
2010
Makarian's Chain- 5/5/2010
2011
NGC 891- 11/18/2011
M31- 11/25/2011
2016
M31- 8/23/16