Using a technique based on the work of the 1902 Nobel Prizewinner, Pieter Zeeman, an international team of astronomers have, for the first time, provided conclusive proof that the magnetic field close to a number of aging stars is 10 to 100 times stronger than that of our own Sun. These observations suggest a solution to the long outstanding problem as to how, at the end of their lives, a perfectly spherical star can give rise to the complex and often far from spherical structure seen in the resulting planetary nebula - some of the most beautiful objects in our heavens.
The main image is of the "Hourglass" Planetary Nebula observed by the Hubble Space Telescope. The inset image is that of an old "red giant" star of the type observed in the observations, also imaged by the Hubble Space Telescope
When stars like our Sun reach the end of their lives, they eject a large amount of material into the space around them. This material, produced by nuclear fusion reactions in the star, forms a thick dust shell which eventually evolves into a planetary nebula - so called because they appear rather like planetary discs. Due to turbulent gas flows around the star the strong magnetic fields that have been discovered will have very different shapes. The material which is ejected from the star "feels" this strong magnetic field and so, as a result, the planetary nebula can have a very complicated structure. The ejected material, containing elements such as carbon and oxygen, in eventually recycled into new stars and planets and the building blocks of life itself.
The group, lead by Wouter Vlemmings of Leiden Observatory, observed 4 old stars with the U.S. National Science Foundation`s VLBA, the network of radio telescopes operated by the American National Radio Astronomy Observatory. They detected radio emission which originates from clouds of water vapor ejected by the stars. In some circumstances, such a cloud can become a maser: the equivalent of a laser for radiation with longer wavelengths. One specific frequency of the emitted radiation, which is characteristic for the H2O molecule, is amplified enormously, resulting in a bright, clear signal. In this signal, the group was able to detect the Zeeman-effect for the first time: subtle changes in the spectrum of the emission that can only be caused by a strong magnetic field at the location of the maser.
Wouter Vlemmings | alfa
Neutron star merger directly observed for the first time
17.10.2017 | University of Maryland
Breaking: the first light from two neutron stars merging
17.10.2017 | American Association for the Advancement of Science
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
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