Giant Bubble Evolving into One of the Brightest Stars in Milky Way

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RCW 120 is a galactic bubble that harbors a very large surprise. A surprise that’s at least eight times the mass of the sun. Nestled in the shell around this large bubble is an embryonic star that looks set to turn into one of the brightest stars in our Milky Way galaxy.

The galactic bubble is known as RCW 120. It lies about 4,300 light-years away and has been formed by a star at its center. The star is not visible at these infrared wavelengths but pushes on the surrounding dust and gas with nothing more than the power of its starlight. In the 2.5 million years the star has existed, it has raised the density of matter in the bubble wall so much that the quantity trapped there can now collapse to form new stars.

The bright knot to the right of the base of the bubble in the Herschel Space Observatory image below is an unexpectedly large, embryonic star, triggered into formation by the power of the central star. Herschel’s observations have shown that it already contains between eight to 10 times the mass of our sun. The star can only get bigger because it is surrounded by a cloud containing an additional 2,000 solar masses.

(via dailygalaxy)