Abell 104 - Galaxy Cluster
I don't know why I'm always attracted to the deepest depths of the universe - but distances of more than 1 billion light years and distant clusters
of galaxies have a magical attraction on me.
Maybe it's the thought of being surrounded by the blackness of the universe and seeing things with my own eyes that are simply unimaginably far
away from us. Or maybe it's the knowledge that galaxy clusters are among the largest structures in existence - millions of light years across.
Populated by many dozens or even hundreds of galaxies, all interwoven in the cosmic dance of gravity, and in some distant future merged into a
single giant elliptical galaxy, having lost all trace of individuality.
The galaxy cluster Abell 104 in the constellation Pisces directly at the border to Andromeda is such a candidate. It is 1.1 billion lightyears away
and has a redshift of z=0.082. It is moving away from us with a speed of 23,600 km/s - that is nearly 10% of the speed of light. It is centered
around a 10mag star, another bright 9mag star is a few arcminutes away, which makes the search quite easy. This star chain, which includes a third
faint star, brings back memories of Abell 2065.
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When I visited the cluster with my 20" f/3.2 telescope in early October, the air was quite chilly. The sky was transparent and the seeing was
good. Optimal conditions therefore. Because just like faint stars, very faint galaxies benefit from steady air. With poor seeing it is almost impossible
to observe such objects.
The position was found quickly and a bright star chain showed me the way to the center of Abell 104. When I arrived there, I took the POSS printout
in which I had already marked the galaxies that were doable. I pulled my black cloth over my head, plugged in my headphones, and set off on my
journey through the galaxy cluster Abell 104. Faint galaxy after faint galaxy flashed against the deep black sky and was crossed off on the map. But
not every galaxy got a cross, because they were just too faint for my 20" Dobson. Since two galaxies are foreground objects, by the end of this session
I was able to pinpoint 22 galaxies in Abell 104.
A little over half an hour was spent on this trip that took me 1 billion into the past. It is a wonderful feeling to reappear under the black cloth after
this time and suddenly find myself back on our home planet.
