MELBOURNE: Over 70 years after Indian astrophysicist and Nobel laureate Subrahmanyan Chandrasekhar expected that rapidly revolving stars would emit polarised light, researchers in Australia have noticed the phenomenon for the first time.
Experts from the University of New South Wales (UNSW) in Australia and University College London in the united kingdom used an extremely sensitive device to identify the polarised light from Regulus, one of the brightest superstars in the full night sky.
The gear provided unprecedented insights into the star, which is in the constellation Leo, allowing the scientists to determine its rate of spinning and the orientation in space of the star’s spin axis.
“We found Regulus is rotating so quickly it is near to flying aside, with a spin rate of 96.5 percent of the angular velocity for a break-up,” said Daniel Cotton, from UNSW.
“It is content spinning at approximately 320 kilometers per second equal to journeying from Sydney to Canberra in under another,” said Cotton.
In 1946, Chandrasekhar predicted the emission of polarised light from the edges of famous actors, prompting the introduction of sensitive instruments called stellar polarimeters to attempt to detect this effect.
Optical polarisation is a way of measuring the orientation of the oscillations of the light beam to its direction of travel.
In 1968, other researchers built on Chandrasekhar’s work to predict that the distorted, or squashed, form of a rotating star would lead to the emission of polarised light rapidly, but its detection now has eluded astronomers until.
“The instrument we have built, the High Precision Polarimetric Device (HIPPI) is the world’s most delicate astronomical polarimeter,” Cotton said.
“Its high precision has allowed us to identify polarised light from a quickly spinning superstar for the very first time,” he said.
“We have been in a position to combine this new information about Regulus with advanced computer models we’ve developed at UNSW to look for the star’s inclination and rotation rate,” he added.
They have previously been difficult to measure these properties of quickly rotating stars extremely, researchers said.
The information is vital for understanding the lifespan cycles of the majority of the latest and most significant stars in the galaxies, which will be the ones that produce the heaviest elements, such as nickel and iron, in interstellar space, they said.
Regulus is approximately 79 light years away. In August through the total solar eclipse in America, Regulus was one level from sunlight and was just, to numerous people, the only star visible during the eclipse.
The scholarly study was published in the journal Nature Astronomy.