For decades, scientists have observed that Regulus, the brightest star in the constellation Leo, spins much faster than the sun. But thanks to a powerful new telescopic array, astronomers now know with unprecedented clarity what that means to this massive celestial body.
Regulus and the sun are shown as they would appear side by side. The diameter of Regulus at its equator is 4.2 times that of the sun. The dashed line identifies the spin axis of the star, and the 86 degree tilt of the pole from the north is indicated. The phenomenon of “gravity darkening” is responsible for Regulus being brighter at its poles than around its equator. The picture of Regulus is based upon measurements obtained with the CHARA array, which does not by itself produce a true image of the star.
A group of astronomers, led by Hal McAlister, director of Georgia State Universitys Center for High Angular Resolution Astronomy, have used the centers array of telescopes to detect for the first time Regulus rotationally induced distortions. Scientists have measured the size and shape of the star, the temperature difference between its polar and equatorial regions, and the orientation of its spin axis. The researchers observations of Regulus represent the first scientific output from the CHARA array, which became routinely operational in early 2004.
Most stars rotate sedately about their spin axes, McAlister says. The sun, for example, completes a full rotation in about 24 days, which means its equatorial spin speed is roughly 4,500 miles per hour. Regulus equatorial spin speed is nearly 700,000 miles per hour and its diameter is about five times greater than the suns. Regulus also bulges conspicuously at its equator, a stellar rarity.
Hal McAlister | EurekAlert!
Pulses of electrons manipulate nanomagnets and store information
21.07.2017 | American Institute of Physics
Vortex photons from electrons in circular motion
21.07.2017 | National Institutes of Natural Sciences
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
21.07.2017 | Earth Sciences
21.07.2017 | Power and Electrical Engineering
21.07.2017 | Physics and Astronomy