The jets are a byproduct of gas accretion around newly forming stars and shoot off at supersonic speeds of about 100 miles per second in opposite directions through space.
These phenomena are providing clues about the final stages of a star’s birth, offering a peek at how our Sun came into existence 4.5 billion years ago.
Hubble’s unique sharpness allows astronomers to see changes in the jets over just a few years’ time. Most astronomical processes change over timescales that are much longer than a human lifetime.
A team of scientists led by astronomer Patrick Hartigan of Rice University in Houston, Texas, collected enough high-resolution Hubble images over a 14-year period to stitch together time-lapse movies of the jets ejected from three young stars.
Never-before-seen details in the jets’ structure include knots of gas brightening and dimming over time and collisions between fast-moving and slow-moving material, creating glowing arrowhead features. The twin jets are not ejected in a steady stream, like water flowing from a garden hose. Instead, they are launched sporadically in clumps. The beaded-jet structure might be like a “ticker tape,” recording how material episodically fell onto the star.
“For the first time we can actually observe how these jets interact with their surroundings by watching these time-lapse movies,” said Hartigan. “Those interactions tell us how young stars influence the environments out of which they form. With movies like these, we can now compare observations of the jets with those produced by computer simulations and laboratory experiments to see what aspects of the interactions we understand and what parts we don’t understand.”
Jets are an active, short-lived phase of star formation, lasting only about 100,000 years. Astronomers don’t know precisely what role jets play in the star-formation process or exactly how the star unleashes them. The jets appear to work in concert with magnetic fields. This helps bleed excess angular momentum from infalling material that is swirling rapidly. Once the material slows down it feeds the growing protostar, allowing it to fully condense into a mature star.
Hartigan and his colleagues used the Wide Field Planetary Camera 2 to study the jets, called Herbig-Haro (HH) objects, named in honor of George Herbig and Guillermo Haro, who studied the outflows in the 1950s. Hubble followed HH 1, HH 2, HH 34, HH 46, and HH 47 over three epochs, 1994, 1997 to 1998, and 2007 to 2008.
The team used computer software that wove together the observations to generate movies showing continuous motion.
“Taken together, our results paint a picture of jets as remarkably diverse objects that undergo highly structured interactions both within the material in the outflow and between the jet and the surrounding gas,” Hartigan explained. “This contrasts with the bulk of the existing simulations, many of which depict jets as smooth systems.”
Hartigan’s team’s results appeared in the July 20, 2011 issue of The Astrophysical Journal.
For images and more information about these results, visit:http://hubblesite.org/news/2011/20
Donna Weaver / Ray Villard | Newswise Science News
A 100-year-old physics problem has been solved at EPFL
23.06.2017 | Ecole Polytechnique Fédérale de Lausanne
Quantum thermometer or optical refrigerator?
23.06.2017 | National Institute of Standards and Technology (NIST)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology