Scientists are ecstatic over the discovery of the closest and the second brightest among the 20 "hypervelocity" stars found, which they said could unlock hints to the mysteries enshrouding the black hole and the dark matter halo that surrounds our galaxy.
It was an unintentional find since the team of Chinese scientists and U.S. astronomers who found it were busy where conducting other research with stars while using the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) located in China.
LAMOST, which has an aperture of 13.1 feet and houses roughly 4,000 optical fibers, is used by astronomers to determine a star's size, velocity, temperature and luminosity by capturing its light wavelength.
The telescope can survey as many as 4,000 stars straight away. However, due to a speed of 1.4 million mph (almost triple of the usual star's speed of 500,000 mph), the newly-discovered star named "LAMOST-HVS1" caught the scientists' attention. It is the first hypervelocity star spotted by LAMOST.
With its existence confirmed in 2005 by Smithsonian astronomers, a hypervelocity star is believed to have come from a binary star that came too close to an ultra-massive black hole at the center of the Milky Way. The high velocity would capture one of the pair while the other would be hurled further into the emptiness of the infinite space, which then become the hypervelocity star, hence its moniker "outcast star."
"The hypervelocity star tells us a lot about our galaxy - especially its center and the dark matter halo," said Zheng Zheng an assistant professor of physics and astronomy at the University of Utah.
The universe is made up of five percent visible matter while 27 percent of it is invisible. A mysterious dark energy, meanwhile, encompasses the remaining 68 percent and it is responsible for the universe's accelerating expansion.
According to the team, the new hypervelocity star's speed and trajectory can provide clues about the mysterious halo by traveling through it.
"We can't see the dark matter halo, but its gravity acts on the star," explained Zheng, who is also the lead author of the study. "We gain insight from the star's trajectory and velocity, which are affected by gravity from different parts of our galaxy."
LAMOST-HVS1 may be the closest hypervelocity star found but it is 249 quadrillion miles from Earth. That is roughly 1,000,000,000,000,000 miles. While it is 3,400 times brighter and four times hotter than our Sun, this hypervelocity star is younger compared to our source of light, which is 4.6 billion years old, Zheng said.
The discovery of Zheng and his team made it in the Astrophysical Journal Letters journal.
