"The surface of the Earth is the shore of the cosmic ocean... Recently, we've managed to wade a little way out, and the water seems inviting." - Carl Sagan
A galactic bubble with a large surprise
Nestled within the shell around this large bubble is an embryonic star that is already a hefty eight times more massive than our Sun. The Galactic bubble is about 4,300 light-years away and has been blown by a star at its centre. 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.
The pressure exerted on the surrounding material is such that it has begun collapsing into new stars. The bright knot to the right of the base of the bubble is an unexpectedly large, embryonic star, revealed to Herschel’s infrared detectors by heating up the surrounding dense clumps of gas and dust.
Herschel’s observations have shown that it already contains at least eight times the mass of our Sun, and that it is still surrounded by an additional 2000 solar masses of gas and dust from which it can feed further.
Not all of the material will fall onto the star, however, as some will be blasted away by the intense radiation emitted by the star. Some stars reach an impressive 150 solar masses, but just how large this stellar embryo will grow remains to be seen.
Image credit: ESA/PACS/SPIRE/HOBYS Consortia