RCW 120 is a bubble blown by a central star (not visible at these
infrared wavelengths) that has exerted enough pressure in the bubble
‘walls’ that material can begin collapsing into the next generation of
star. The bright knot in the bottom right of the bubble is one such
stellar embryo, which is surrounding by material amounting to 2000 solar
masses. The star already has a mass of about 8–10 Suns, and will likely
grow larger still. RCW 120 lies about 4300 light-years away.
The
image was created from data collected using the PACS and SPIRE
instruments on ESA’s Herschel space observatory, covering wavelengths of
100µm (blue), 160µm (green) and 250µm (red). Copyright: ESA/PACS/SPIRE/HOBYS Consortia
Nestled within the shell around this large bubble is an embryonic star
that is already a hefty eight times more massive than our Sun.
This image, by ESA’s Herschel space observatory, was originally presented in the first announcement of scientific results from the mission in May 2010.
This week Herschel scientists will meet again at ESA’s ESTEC
establishment in the Netherlands to present, discuss, and take stock of
the scientific breakthroughs of the entire mission at The Universe Explored by Herschel symposium.
The Galactic bubble shown in this image was just one of many surprising results of the mission.
It is about 4300 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.
This week, scientists will not only discuss star formation, but also
what the Herschel space observatory has revealed about planetary system
evolution, galaxy formation, the interstellar medium and more. A full
programme can be found here.
Herschel was launched on 14 May 2009 and completed science observations on 29 April 2013.
Source: ESA
