Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UI researchers discover star orbiting a ’medium-sized’ black hole

06.01.2006


University of Iowa researchers have found a star orbiting a "medium-sized" black hole -- about 1,000 times more massive than the sun -- in the nearby starburst galaxy M82, a development that may help explain how medium-sized black holes form and evolve, according to a paper to be published in the Jan. 5 issue of Science Express, the online version of the journal Science.



Philip Kaaret, associate professor in the UI College of Liberal Arts and Sciences Department of Physics and Astronomy, made the discovery indirectly, by detecting modulations in X-rays produced by the black hole. His associates in the work were assistant professor Cornelia Lang and student Melanie Simet, a senior from Cedar Falls, Iowa.

"We discovered that the X-rays from the black hole get repeatedly brighter and dimmer every 62 days," he said. "This told us that the companion star orbiting around the black hole makes one orbit every 62 days. This, in turn, told us that the companion star has to be a giant star -- a phase in the evolution of a star when it becomes extremely bloated."


Kaaret said that the discovery may help confirm the existence of a class of black holes having a mass between 100 and 10,000 times that of the sun. That would make the objects larger than black holes produced by the collapse of a single normal star and smaller than the supermassive black holes found at the centers of galaxies.

"The discovery also explains why this black hole is so bright in X-rays. It’s because the black hole can pull gas directly off from the outer layers of the giant star," Kaaret said.

The UI researchers, who used an x-ray telescope called the "Proportional Counter Array on NASA’s Rossi X-Ray Timing Explorer," note that their discovery will await validation by new observations to be made with the Proportional Counter Array and other X-ray telescopes.

"This first discovery proves our technique, and we hope to make more discoveries with new X-ray observations of other black holes," Kaaret said.

Gary Galluzzo | EurekAlert!
Further information:
http://www.uiowa.edu

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

NSF-supported researchers to present new results on hurricanes and other extreme events

19.07.2018 | Earth Sciences

Scientists uncover the role of a protein in production & survival of myelin-forming cells

19.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>