Supernovas may be one of the answers

Feb 25, 2009 20:01 GMT  ·  By

Stellar dust can be found in nearly every portion of a galaxy, and its role is one of the most important in the Universe – more specifically that of facilitating the formation of stars and planets, implicitly. Up until this point, astronomers have had no idea as to what the actual origin of this dust might be, even though they do have a few theories, such as the one saying that the matter is formed as drops, in the intense stellar winds of stars in their supernova stage.

A new study conducted by astronomers at the University of Nottingham, led by Loretta Dunne, shows a potential source for the cosmic dust, and namely supernova remnants. In order to reach this conclusion, the team has looked at the Cassiopeia A field, a remnant that was generated more than 300 years ago, when a nearby star blew up. Now, this particular formation is spilling out enormous amounts of dust, even if the recorded temperature in the clouds is of minus 250 degrees Celsius.

For the new research, the team has used the SCUBA polarimeter instrument on the James Clerk Maxwell Telescope, in Hawaii. This has allowed them to detect the motion of dust particles spinning in the magnetic field of the supernova remnants. By switching the angle of the tool, they have been able to observe spinning speeds and orbits, and to learn that the polarization signal emitted by Cassiopeia A is the strongest ever recorded.

“It is like nothing we’ve ever seen. It could be that the extreme conditions inside the supernova remnant are responsible for the strong polarized signal, or it could be that the dust grains themselves are highly unusual,” Dunne says.

“It could be that the material we're seeing is in the form of iron needles – exotic, slender, metallic whiskers. If these grains are distributed throughout the Universe, they may be re-radiating microwaves. This has major consequences for our understanding of the cosmic microwave background – one of the most important building blocks of the Big Bang model of our Universe,” Professor Rob Ivison, a team member and a scientist at the Astronomy Technology Centre in Edinburgh, which is part of the Science and Technology Facilities Council, adds.