Ultrasounds for astronomers?
Determining the age of stars has long been a challenge for astronomers. In experiments published in the journal Science, researchers at KU Leuven's Institute for Astronomy show that 'infant' stars can be distinguished from 'adolescent' stars by measuring the acoustic waves they emit.
In a young region like the so-called Christmas Tree Cluster, stars are still in the process of forming. A star is 'born' once it becomes optically visible (bottom right). During its further evolution, the star contracts and gets smaller in size and hotter until the core temperature is sufficient to start nuclear burning of hydrogen. This marks the end of the stellar childhood phase (bottom left). While the young star evolves from its birth to the beginning of hydrogen burning, its pulsation properties change: the least evolved, i.e., youngest, stars pulsate slower and the most evolved while the oldest stars pulsate faster.
Stars are often born in clusters, the result of contracting molecular clouds of gas and dust particles. As a star evolves from infant to adolescent, gravitational pull causes it to contract. It gets smaller in size and hotter until the core temperature is sufficient to start nuclear burning of hydrogen. At this point, the star stabilizes and becomes an 'adult'. It stays this way for vast tracts of time.
Determining the age of a young star is far from simple, and knowing which molecular cloud a star comes from gives only a vague idea of its age. But researchers have come up with a way to determine the age of stars by measuring their acoustic vibrations using ultrasound technology similar to that used in the field of medicine.
Acoustic vibrations – sound waves – are produced by radiation pressure inside stars. First author Konstanze Zwintz, a postdoctoral researcher at KU Leuven's Institute for Astronomy, and her colleagues studied the vibrations of 34 stars aged under 10 million years and sized between one and four times the mass of our sun.
"Our data shows that the youngest stars vibrate slower while the stars nearer to adulthood vibrate faster. A star's mass has a major impact on its development: stars with a smaller mass evolve slower. Heavy stars grow faster and age more quickly," says Dr. Zwintz.
While theoretical physicists have posited before that young stars vibrate differently than older stars, Zwintz' study is the first to confirm these predications using concrete data from outer space.
"We now have a model that more precisely measures the age of young stars," says Zwintz. "And we are now also able to subdivide young stars according to their various life phases."
The researchers studied the nebula known commonly as the Christmas Tree Cluster. Their data was obtained from the Canadian MOST satellite and the European CoRoT satellite as well as from ground-based facilities such as the European Southern Observatory (ESO) in Chile.
Dr. Konstanze Zwintz | Eurek Alert!
Spiral arms: not just in galaxies
30.09.2016 | Max-Planck-Institut für Radioastronomie
Discovery of an Extragalactic Hot Molecular Core
29.09.2016 | National Astronomical Observatory of Japan
Heavy construction machinery is the focus of Oak Ridge National Laboratory’s latest advance in additive manufacturing research. With industry partners and university students, ORNL researchers are designing and producing the world’s first 3D printed excavator, a prototype that will leverage large-scale AM technologies and explore the feasibility of printing with metal alloys.
Increasing the size and speed of metal-based 3D printing techniques, using low-cost alloys like steel and aluminum, could create new industrial applications...
Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.
Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...
Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.
Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
30.09.2016 | Event News
29.09.2016 | Event News
28.09.2016 | Event News
30.09.2016 | Materials Sciences
30.09.2016 | Earth Sciences
30.09.2016 | Life Sciences