An Ultracompact Dwarf Galaxy

M60-UCD1_by_HSTM60-UCD1 is an ultracompact dwarf galaxy. Half of its stellar mass is in the central sphere only 160 light years in diameter. It is probably the densest known galaxy with over one hundred stars per cubic light-year, and it is the smallest and least massive galaxy known to host a central black hole. It is also the most massive ultracompact dwarf galaxy known. It is also one of the oldest galaxies in the universe.

Image Credit: NASA

6 thoughts on “An Ultracompact Dwarf Galaxy

  1. It is also one of the oldest galaxies in the universe.

    Never expanded or eventually all galaxies, Milky Way Bar included, will be equally dense on their way to re-compacting back into their black hole?

  2. Another way to look at the star density is we have 9 stars within 10 light years of us for an average density of 1 star per 111 cubic light years vs the 100+ per cubic light year in this galaxy!

    How close would the nearest star be? Well, a cubic light year breaks down to 1728 cubic light months for an average of one star per 17 cubic light months. That means we would likely have four stars within two light months of us! I’m guessing that would probably be close to a full moon’s worth of light.

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