Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

AMBER looks into the cradle of planets

29.11.2005


International team of astronomers uses a new infrared interferometer at the VLT to get surprising views of cosmic disks of dust and gas



A research team investigated a disk of gas and dust surrounding a young star, as well as the stellar winds which emanate from that star. The team found unique, previously unknown characteristics of the innermost environment around the star. Another research group carried out the first-ever analysis of the gas and dust material surrounding a "supergiant" star. All of the observations have now been published in the renowned journal Astronomy & Astrophysics.

In order to investigate the immediate environment of a young star with unprecedented accuracy, an international team of researchers led by Fabien Malbet of the University of Grenoble used two telescopes of the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory (ESO), which is located on the Cerro Paranal mountain in Chile. Each of the huge telescope mirrors has a diameter of 8.2 metres; the distance between them is 47 meters. Both telescopes took pictures in the infrared spectral range of the young star MWC 297. Combining these infrared images in the central VLTI beam combination laboratory provides a very high angular resolution. This technique is known as infrared interferometry. The new interferometric instrument AMBER at the VLTI allowed both, the interferometric combination of images from both telescopes and the spectroscopic decomposition of the light.


The observation and analysis of the young star MWC 297 is one of the first results of the new AMBER instrument. It showed that MWC 297 is surrounded by a huge disk of dust and gas, known as an accretion disk. The disk emits radiation of many different wavelengths within the infrared range. The star also has an intense stellar wind blowing out at high speed. In the infrared range, the wind only radiates the light of a single hydrogen emission line, the Brackett-gamma line. AMBER made it possible to measure both components of the light separately and thus, for the first time ever, to determine the physical extent of both the accretion disk and the stellar wind. The disk’s infrared radiation is produced in a region with a size of 1.75 Astronomical Units. One Astronomical Unit represents the distance from the earth to the sun: 150 million kilometers. The stellar wind’s hydrogen light, on the other hand, comes from a considerably larger area of about 2.5 astronomical units.

The scientists used a new modelling method to evaluate the measured data, interpreting their observations of both the accretion disk and the stellar wind. The star emits the stellar wind’s ionised gas in almost all spatial directions. Although the gas near the disk moves at an expansion velocity of only 60 kilometers per second, the stellar wind in the direction of the poles blows at up to 600 kilometers per second. With AMBER, scientists can investigate the physical properties of dust and gas in the immediate vicinity of stars with the highest resolution ever. These are the regions where planets form and we can get entirely new information about conditions underlying the process.

The second AMBER research project, led by Armando Domiciano de Souza at the Max Planck Institute for Radio Astronomy in Bonn, involved combining light from three of the four large 8.2 meter telescopes at the VLTI. Instead of a young star, the observed object was a massive, evolved star named CPD-57°2874. This "supergiant star" is about 10,000 times more luminous and about 50 times larger than our sun. At a distance of 8,000 light years, it is some 10 times further from the Earth than MWC 297. AMBER’s detailed observations of this star have contributed to a better understanding of the physical properties of the material in its environment.

The AMBER interferometric instrument was built for ESO by an international consortium which includes the following institutions: Laboratoire Universitaire d’Astrophysique de Nice, Laboratoire d’Astrophysique de l’Observatoire de Grenoble, Laboratoire Gemini de l’Observatoire de la Cote d’Azur, Max Planck Institute for Radio Astronomy in Bonn, and Osservatorio Astrofisico di Arcetri in Florence. The Principal Investigator of the project is Romain Petrov at the University of Nice.

The development of the infrared camera and the data recording software was led by Professor Gerd Weigelt, Director of the Max Planck Institute for Radio Astronomy in Bonn.

Prof. Gerd Weigelt | EurekAlert!
Further information:
http://www.mpifr-bonn.mpg.de

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

NSF-supported researchers to present new results on hurricanes and other extreme events

19.07.2018 | Earth Sciences

Scientists uncover the role of a protein in production & survival of myelin-forming cells

19.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>