Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rapidly rotating star dubbed ’King of Spin’ by research team

11.01.2005


New ultraviolet observations indicate a Milky Way star is spinning nearly 200 times faster than Earth’s sun, the probable result of a merger between two sun-like stars whose binary orbit recently collapsed, according to a University of Colorado at Boulder astronomer.

The yellow giant, known as FK Comae Berenices, or FK Com, is 10 times larger than the sun and is emitting spectacular amounts of X-rays, ultraviolet light and radio waves as it rotates furiously, said Senior Research Associate Thomas Ayres of CU-Boulder’s Center for Astrophysics and Space Astronomy.

Dubbed the "King of Spin" by the research team, FK Com is the namesake of a rare class of fast-rotating yellow giants noted for high levels of coronal magnetic activity, said Ayres. "FK Com objects are oddballs because most giant stars rotate very slowly. That’s why many theorists now believe binary mergers are the best way to explain the existence of these rare, ultra-fast rotators," he said.



Ayres presented a paper on the subject at the 205th meeting of the American Astronomical Society held Jan. 9 to Jan. 13 in San Diego. Co-authors on the paper include Alex Brown and Graham Harper of CU-Boulder’s CASA, Heidi Korhonen of Germany’s Potsdam University and Seth Redfield of the University of Texas, Austin.

"The negative feedback of magnetic activity on the orbit of stars in close binary systems must produce a number of these objects throughout our galaxy," Ayres said. "It’s fortunate to have one that is so near to its birth, actually its rebirth, and which is close enough to Earth to be observed in detail."

FK Com is located 800 light-years from Earth, relatively close by galactic standards, he said. One light year is about 6 trillion miles.

The team observed FK Com with the Far Ultraviolet Spectroscopic Explorer satellite, or FUSE, launched in 1999 to probe the far UV radiation portion of the light spectrum invisible to the Hubble Space Telescope. The researchers used FUSE to observe the star for four hours on Feb. 12, 2004.

The rotation of FK Com recorded in UV light is roughly 200 miles per second, about twice that measured previously in the visible part of the spectrum, he said.

FK Com is covered with dark regions that are similar to sunspots but much larger and more pervasive, Ayres said. "This object seems to be flaring practically all of the time and often doubles or triples its vast X-ray output, which is already 100,000 times that of the sun, during these episodes."

The speedy rotation seen in the UV spectrum likely is caused by the star’s slingshot prominences, which are massive, hot tubes of gas similar to magnetic loops that shoot out from the surface of the sun into its corona, he said. Up to several million miles long, the prominences are whipping around the star at much higher speeds than the surface rotation, much like the outer edge of a phonograph record moves faster than the inner part.

The research team believes the coronal wind near such prominences is carrying away large amounts of angular momentum, or spin, from the star. This eventually will "brake" the star’s fast rotation, much like a twirling figure skater extends her arms in order to slow down, Ayres said.

FK Com is an "extreme case" of sun-like magnetic activity, he said. "By examining the extremes closely, we can gain insight into the inner workings of these violent cosmic phenomena, which studies of our own, very inactive sun could not reveal."

The international FUSE mission involves science team members from the United States, France and Canada. Four FUSE telescopes collect and funnel UV light into a $9 million spectrograph, which was designed and built at CU-Boulder and breaks down the light like sunbeams passing through a prism.

The FUSE mission is managed and operated for NASA by Johns Hopkins University in Baltimore, Md. FUSE observations and research on FK Com was supported by NASA through the FUSE Guest Investigator program.

Thomas Ayres | EurekAlert!
Further information:
http://www.colorado.edu

More articles from Physics and Astronomy:

nachricht Space radiation won't stop NASA's human exploration
18.10.2017 | NASA/Johnson Space Center

nachricht Study shows how water could have flowed on 'cold and icy' ancient Mars
18.10.2017 | Brown University

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: Neutron star merger directly observed for the first time

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...

Im Focus: Breaking: the first light from two neutron stars merging

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....

Im Focus: Smart sensors for efficient processes

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...

Im Focus: Cold molecules on collision course

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...

Im Focus: Shrinking the proton again!

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>