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Planck reveals complexity
of star formation

DR EMILY BALDWIN
ASTRONOMY NOW
Posted: 27 April 2010


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New images from ESA's Planck space observatory reveal the complex driving forces behind star formation, giving astronomers new insight into the processes that sculpt the dust and gas of our Galaxy.

An active star-formation region in the Orion Nebula, showing also the Horsehead Nebula and Barnard's Loop. This image covers a region of 13x13 degrees. It is a three-colour combination constructed from three of Planck's nine frequency channels: 30, 353 and 857 GHz. Image: ESA/LFI & HFI Consortia.

The Planck observatory was launched nearly a year ago and with its microwave vision it can penetrate through the shrouds of dust that optical telescopes are blinded by to reveal intricate glowing structures of star-forming gas and dust.

One of Planck's latest study regions is the well-known Orion Nebula, standing out in the first image (above) as the glowing bright spot at the lower centre. The glowing red region above and to the right of that is the Horsehead Nebula, and the giant red arc is known as Barnard’s Loop, a suspected blast wave from a star that expired inside the region around two million years ago but has left its mark as a 300 light-year diameter bubble rippling through the stellar neighbourhood. The second image (below) details the Perseus region, a slightly calmer region of star-formation, compared with Orion.

A low activity, star-formation region in the constellation Perseus, as seen with Planck. This image covers a region of 30x30 degrees. It is a three-colour combination constructed from three of Planck's nine frequency channels: 30, 353 and 857 GHz. Image: ESA/LFI & HFI Consortia.

Both images reveal three physical processes taking place in the dust and gas of the interstellar medium, covering the frequency range of the space telescope. At lowest frequencies emission caused by high-speed electrons interacting with the Galaxy’s magnetic fields is captured, along with an additional diffuse component that comes from spinning dust particles emitting at these frequencies. At intermediate wavelengths of a few millimetres, the emission is from gas heated by newly formed hot stars.

At higher frequencies Planck can pick out the heat emitted by the cold cores of dust clouds, which cocoon the seeds of future stars. Once born, the newborn stars sweep away the surrounding material. This balancing act of cloud collapse and dispersion acts to regulate the number of stars born in our Galaxy, and thanks to Planck's frequency range this process will be explored with greater clarity than ever, because, for the first time, data will be provided on several major emission mechanisms in one go.

The Planets
From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.
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Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.
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3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!
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