This
Astrobin Debut Object, also known as Mrk 1094, is a blue compact dwarf galaxy located 130 million light years away in the constellation of Orion at a declination of -3 degrees. It is a magnitude 14.4 galaxy which spans 1 arc-minutes in our apparent view. This corresponds to a diameter of 20,000 light years. Be careful not to confuse this object with
Zw III 33, which I have done several times now.
This object is classified as a blue compact dwarf galaxy (BCD). BCDs are small, faint, and blue star-forming galaxies. They are blue because they contain massive young stars that emit high energy radiation. They have little dust. Gas (hydrogen plus helium) contributes between 40% and 95% of the mass of BCDs. Many scientists believe that these small, active galaxies have served as the building blocks for larger galaxy formation. My Astrobin collection of BCDs is
here.
Since spiral density waves are not present in dwarf galaxies, it is not clear how their star formation is triggered. One theory is that interactions with nearby dim (but still massive) companions increase their gas density high enough to trigger this star formation. Zw II 33 is an important BCD because a massive but optically dim companion has been found. This companion, Zw II 33B, contains almost as much mass in H1 as Zw II 33. The companion can be seen in the image about 5 arc-minutes below Zw II 33.
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