Nearly all galaxies, including our own
can be found in groups, or galaxy clusters. The following
pictures are of galaxy clusters. As you are looking for different
types of galaxies in these pictures, be careful that you do not
mistake faint foreground stars for galaxies. The trick: in pictures
taken through telescopes stars usually have what appear to be four
"points" on them - now we know that stars are really round
spheres, so it turns out that these "points" are caused by
the telescope instrument itself and really don't exist, however they
can be used to distinguish foreground stars from galaxies (i.e. in the
first picture there is a bright star toward the upper left corner of
the picture, and another in the bottom right corner, can you find
them?)
In the next picture, can you spot: an
elliptical? two colliding galaxies? a face-on spiral? an edge-on
spiral?
Can you spot: an elliptical? an edge-on spiral? a face-on spiral?
Recognize this next galaxy cluster (recall Lab 13)? Can you spot: an elliptical? a face-on spiral? an edge-on spiral? a pair of colliding galaxies?
This next picture is of the Hubble Deep Field (it is the same picture that is on the front cover of your ASTRO 011 Lab Manual) - these are the youngest galaxies ever observed in visible light. Nearly EVERYTHING in this image is a galaxy - with the exception of about six foreground stars that are part of our Milky Way. Can you find: a face-on spiral? an edge-on spiral? an elongated elliptical? a round elliptical? an irregular? two colliding galaxies?
Did you get stuck? Here are a few identifications for the first three images (NOTE: they are not the only "correct" answers, just a few of the easiest ones in each image to identify).