Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New astronomical phenomenon: Coreshine provides insight into stellar births

24.09.2010
Science is literally in the dark when it comes to the birth of stars, which occurs deep inside clouds of gas and dust: These clouds are completely opaque to ordinary light.

Now, a group of astronomers has discovered a new astronomical phenomenon that appears to be common in such clouds, and promises a new window onto the earliest phases of star formation. The phenomenon – light that is scattered by unexpectedly large grains of dust, which the discoverers have termed “coreshine” – probes the dense cores where stars are born. The results are being published in the September 24, 2010 edition of the journal Science.


The molecular cloud CB 244 in the constellation Cepheus, 650 light-years from Earth. This false-color image shows mid-infrared light scattered by larger grains of dust in the interior of the cloud, the newly discovered “coreshine”. Image: MPIA

Stars are formed as the dense core regions of cosmic clouds of gas and dust (“molecular clouds”) collapse under their own gravity. As a result, matter in these regions becomes ever denser and hotter until, finally, nuclear fusion is ignited: a star is born. This is how our own star, the Sun, came into being; the fusion processes are responsible for the Sun’s light, on which life on Earth depends. The dust grains contained in the collapsing clouds are the raw material out of which an interesting by-product of star formation is made: solar systems and Earth-like planets.

What happens during the earliest phases of this collapse is largely unknown. Enter an international team of astronomers led by Laurent Pagani (LERMA, Observatoire de Paris) and Jürgen Steinacker (Max Planck Institute for Astronomy, Heidelberg, Germany), who have discovered a new phenomenon which promises information about the crucial earliest phase of the formation of stars and planets: “coreshine”, the scattering of mid-infrared light (which is ubiquitous in our galaxy) by dust grains inside such dense clouds. The scattered light carries information about the size and density of the dust particles, about the age of the core region, the spatial distribution of the gas, the prehistory of the material that will end up in planets, and about chemical processes in the interior of the cloud.

The discovery is based on observations with NASA’s Spitzer Space Telescope. As published this February, Steinacker, Pagani and colleagues from Grenoble and Pasadena detected unexpected mid-infrared radiation from the molecular cloud L 183 in the constellation Serpens Cauda (“Head of the snake”), at a distance of 360 light-years. The radiation appeared to originate in the cloud’s dense core. Comparing their measurements with detailed simulations, the astronomers were able to show that they were dealing with light scattered by dust particles with diameters of around 1 micrometer (one millionth of a meter). The follow-up research that is now being published in Science clinched the case: The researchers examined 110 molecular clouds at distances between 300 and 1300 light-years, which had been observed with Spitzer in the course of several survey programs. The analysis showed that the L 183 radiation was more than a fluke. Instead, it revealed that coreshine is a widespread astronomical phenomenon: Roughly half of the cloud cores exhibited coreshine, mid-infrared radiation associated with scattering from dust grains in their densest regions.

The discovery of coreshine suggests a host of follow-on projects – for the Spitzer Space Telescope as well as for the James Webb Space Telescope, which is due to be launched in 2014. The first coreshine observations have yielded promising results: The unexpected presence of larger grains of dust (diameters of around a millionth of a meter) shows that these grains begin their growth even before cloud collapse commences. An observation of particular interest concerns clouds in the Southern constellation Vela, in which no coreshine is present. It is known that this region was disturbed by several stellar (supernova) explosions. Steinacker and his colleagues hypothesize that these explosions have destroyed whatever larger dust grains had been present in this region.

Contact information

Dr. habil. Jürgen Steinacker (Lead author)
Max Planck Institute for Astronomy
Phone: (+33) 476 43 02 32
E-mail: stein@mpia.de
Prof. Dr. Thomas Henning (Co-author)
Max Planck Institute for Astronomy
Phone: (+49|0) 6221 – 528 200
E-mail: henning@mpia.de
Dr. Markus Pössel (Public relations)
Max Planck Institute for Astronomy
Phone: (+49|0) 6221 – 528 261
E-mail: poessel@mpia.de

Dr. Markus Pössel | Max-Planck-Institut
Further information:
http://www.mpia.de

More articles from Physics and Astronomy:

nachricht Basque researchers turn light upside down
23.02.2018 | Elhuyar Fundazioa

nachricht Attoseconds break into atomic interior
23.02.2018 | Max-Planck-Institut für Quantenoptik

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>