Abell 225 - Galaxy Cluster
Abell 225 is a galaxy cluster located in the constellation Pisces about 3° north of the well-known galaxy Messier 74. It is about 920 million light-years
away from Earth and has a redshift of z=0,069. Every second it moves away from us by another 20,000 kilometers because of the expansion of the universe.
In the center we find an elliptical galaxy with the meaningful name "2MASX J01384892+1849311", which is the brightest galaxy in this cluster. It has an
apparent magnitude of 15.6mag, which corresponds to an absolute brightness of M= -21.7mag and a luminosity of 40 billion suns. From the size of 0.48'
its diameter can be determined to 130,000 light-years - so it is similar in size to Messier 87.
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On a dark night I could make a visit to Abell 225 with my 20" f/3 telescope. In the field of view there are some brighter stars (among them a double star), which
make the orientation a little bit easier.
With a magnification of 270x I could find 10 galaxies, but all of them could only be seen with averted vision. The most luminous galaxy was the above
mentioned elliptical galaxy in the center, which became much brighter towards the center. The other galaxies were all more or less homogeneous and featureless.
