Findings have implications on evolution of massive stars
Observations using NASA's Chandra X-ray Observatory revealed that the unusually large magnetosphere around an O-type star called NGC 1624-2 contains a raging storm of extreme stellar winds and dense plasma that gobbles up X-rays before they can escape into space.
Findings from a team of researchers led by Florida Institute of Technology Assistant Professor Véronique Petit may help scientists better understand the lifecycle of certain massive stars, which are essential for creating metals needed for the formation of other stars and planets.
The findings will be published Sept. 23 in the journal Monthly Notices of the Royal Astronomical Society from Oxford University Press.
The massive O-type star - the hottest and brightest type of star in the universe - has the largest magnetosphere known in its class. Petit found NGC 1624-2's magnetic field traps gas trying to escape from the star and those gases absorb their own X-rays. The star's powerful stellar winds are three to five times faster and at least 100,000 times denser than our Sun's solar wind. Those winds grapple violently with the magnetic field and the trapped particles create the star's huge aura of hot, very dense plasma.
"The magnetic field isn't letting its stellar wind get away from the star, so you get these big flows that are forced to collide head on at the magnetic equator, creating gas shock-heated to 10 million Kelvin and plenty of X-rays," said Petit, who was part of a team of scientists that discovered the star in 2012. "But the magnetosphere is so large that nearly 80 percent of these X-rays get absorbed before being able to escape into free space and reach the Chandra telescope."
The magnetic field at the surface of NGC 1624-2 is 20,000 times stronger than at the surface of our Sun. If NGC 1624-2 was in the center of our solar system, loops of dense, hot plasma would extend nearly to the orbit of Venus.
Only one in 10 massive stars have a magnetic field. Unlike smaller stars like our sun that generate magnetism with an internal dynamo, magnetic fields in massive stars are "fossils" left over from some event in its early life, perhaps from a collision with another star.
Petit and her team, including Florida Tech graduate student Rebecca MacInnis, will know even more about the NGC 1624-2 in October after getting data back from the Hubble Space Telescope that will explore the dynamics of its trapped wind.
Other scientists who contributed to the research were: David Cohen, Swarthmore College; Gregg Wade, Royal Military College of Canada; Yael Nazé, L'Université de Liège; Stanley Owocki, University of Delaware; Jon Sundqvist, University of Delaware; Asif ud-Doula, Penn State Worthington Scranton; Alex Fullerton, Space Telescope Science Institute; Maurice Leutenegger, NASA/Goddard Space Flight Center and University of Maryland; Marc Gagné, West Chester University.
The paper will be available at midnight Sept. 23 here: http://mnras.
Adam Lowenstein | EurekAlert!
Will Earth still exist 5 billion years from now?
08.12.2016 | KU Leuven
Home computers discover a record-breaking pulsar-neutron star system
08.12.2016 | Max-Planck-Institut für Radioastronomie
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Materials Sciences
08.12.2016 | Materials Sciences
08.12.2016 | Physics and Astronomy