The beautiful Rosette Nebula, aka NGC 2237, lies about 5,200 light-years from Earth in the constellation Monoceros the Unicorn, and is about 130 light-years across. It is an emission nebula, meaning that the gases that compose it glow as they are energized by radiation from local stars. The young stars in the nebula’s center are gravitationally bound to each other; they are an open cluster formed together from the material of the nebula.
Bottom line: A telescopic photo of the Rosette Nebula (NGC 2237), with its central cluster of stars, from EarthSky Community member William Shaheen.
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