If you plot galaxies by the estimated number of stars they have and the calculated rate at which stars are forming, then you find that most galaxies lie along a line.
One popular model of galaxy formation has been that stars form in the central region of a galaxy first, and then later stars further out form.
Astronomers have used a lens bigger than a galaxy to observe the faintest and youngest galaxies ever found.
A candle that burns twice as bright burns half as long, so the saying goes. We’ve thought of galaxies in the same way, in that the brightest galaxies (ones with high rates of star production) are likely in a cosmologically brief period of high activity. But new computer models suggest that might not be the case.
When you think of a galaxy, you likely think of a spiral galaxy. More specifically, you likely imagine a spiral galaxy with two large sweeping arms of stars, such as the image of the Whirlpool Galaxy above. Such a galaxy is known as a grand design spiral, and while it’s an iconic style, it isn’t particularly common among galaxies.
When galaxies collide, the diffuse material surrounding them can collide to produce a radio phoenix.
There’s a new record for the most distant galaxy, or the youngest galaxy depending on your point of view.
There are more nearby dwarf galaxies than we thought, and that may answer a mystery of dark matter.
An ultracompact dwarf galaxy has only about 100 million stars, but they are packed into a region only 200 light years across. In such a galaxy you might see a million stars with the naked eye.