A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar
gas, dust, and ..... At the other extreme, an Sc galaxy has open, well-defined arms
and a small core region. A gal...
Galaxy definition, a large system of stars held together by mutual gravitation and
isolated from similar systems by vast regions of space. See more.
The Earth's galaxy is known as the Milky Way. Our solar system, made up of the
Sun and the planets that encircle it, is a tiny part of that galaxy. A galaxy can also
Sep 17, 2012 ... “Galaxy,” Defined — when I came across a paper with this title while browsing a
recent issue of Astronomical Journal, I was intrigued.
Jan 27, 2011 ... A pair of astronomers call for a debate on a tricky definition. ... You might think a
galaxy is simply a large group of stars, but just how many stars ...
astronomy : any one of the very large groups of stars that make up the universe.
the Galaxy : the galaxy in which we live. : a large group of important or ...
The definition of a galaxy is a large area, particularly of dust, stars and gas that
makes up a universe. An example of a galaxy is the Milky Way. YourDictionary ...
Aug 15, 2013 ... A spiral galaxy has a distinct winding shape. Most of the galaxies observed by
astronomers are spiral galaxies.
a. Any of numerous large-scale aggregates of stars, gas, and dust that constitute
the universe, containing an average of 100 billion (10<sup>11</sup>) solar masses and ...
Apr 26, 2004 ... It is slightly easier to define what doesn't constitute a galaxy. Any object that can
exist as a distinct unit inside a galaxy isn't a galaxy, which ...