Tag Archives: star

Caught in the act: a black hole rips apart an unfortunate star

After passing too close to a supermassive black hole, a star is torn apart into a thin stream of gas, which is then pulled back around the black hole and slams into itself, creating a bright shock and ejecting more hot material, in this artist's conception released on September 26, 2019. Illustration by Robin Dienel/Courtesy of the Carnegie Institution for Science/Handout via REUTERS

By Joey Routlette

WASHINGTON (Reuters) – Scientists have captured a view of a colossal black hole violently ripping apart a doomed star, illustrating an extraordinary and chaotic cosmic event from beginning to end for the first time using NASA’s planet-hunting telescope.

The U.S. space agency’s orbiting Transiting Exoplanet Survey Satellite, better known as TESS, revealed the detailed timeline of a star 375 million light-years away warping and spiraling into the unrelenting gravitational pull of a supermassive black hole, researchers said on Thursday.

The star, roughly the same size as our sun, was eventually sucked into oblivion in a rare cosmic occurrence that astronomers call a tidal disruption event, they added.

Astronomers used an international network of telescopes to detect the phenomenon before turning to TESS, whose permanent viewing zones designed to hunt distant planets caught the beginning of the violent event, proving effective its unique method of surveilling the cosmos.

“This was really a combination of both being good and being lucky, and sometimes that’s what you need to push the science forward,” said astronomer Thomas Holoien of the Carnegie Institution for Science, who led the research published in the Astrophysical Journal.

Such phenomena happen when a star ventures too close to a supermassive black hole, objects that reside at the center of most large galaxies including our Milky Way. The black hole’s tremendous gravitational forces tear the star to shreds, with some of its material tossed into space and the rest plunging into the black hole, forming a disk of hot, bright gas as it is swallowed.

“Specifically, we are able to measure the rate at which it gets brighter after it starts brightening, and we also observed a drop in its temperature and brightness that is unique,” Holoien said.

Observing the oscillation of light as the black hole gobbles the star and spews stellar material in an outward spiral could help astronomers understand the black hole’s behavior, a scientific mystery since physicist Albert Einstein’s work more than a century ago examined gravity’s influence on light in motion.

(Reporting by Joey Roulette; Editing by Will Dunham)

In first, scientists detect gravitational waves and light from star collision

An artist’s illustration of two merging neutron stars. The rippling space-time grid represents gravitational waves that travel out from the collision, while the narrow beams show the bursts of gamma rays that are shot out just seconds after the gravitational waves.

By Scott Malone

CAMBRIDGE, Mass. (Reuters) – Scientists in the United States and Europe have for the first time detected gravitational waves, the ripples in space and time predicted by Albert Einstein, at the same time as light from the same cosmic event, according to research published on Monday.

The waves, caused by the collision of two neutron stars some 130 million years ago, were first detected in August in the Laser Interferometer Gravitational-Wave Observatories, known as LIGO, in Washington state and Louisiana as well as at a third detector, named Virgo in Italy.

Two seconds later, observatories on earth and in space detected a burst of light in the form of gamma rays from the same path of the southern sky, which analysis showed likely to be from the same source.

Less than two years have passed since scientists working at the Massachusetts Institute of Technology and the California Institute of Technology first detected gravitational waves coming off two black holes.

The gravitational waves had been predicted by Einstein in 1916, as an outgrowth of his groundbreaking general theory of relativity, which depicted gravity as a distortion of space and time triggered by the presence of matter.

Three U.S. scientists who made that discovery were awarded the Nobel prize in physics earlier this month.

The findings published on Monday help confirm Einstein’s theory, said the researchers, whose work was published in Physical Review Letters.

“From informing detailed models of the inner workings of neutron stars and the emissions they produce, to more fundamental physics such as general relativity, this event is just so rich,” said MIT senior research scientist David Shoemaker. “It is a gift that will keep on giving.”

The LIGO instruments work in unison and use lasers to detect remarkably small vibrations from gravitational waves as they pass through the earth.

Previously, scientists could only study space by observing electromagnetic waves such as radio waves, visible light, infrared light, X-rays and gamma rays. Those waves encounter interference as they travel across the universe, but gravitational waves do not, meaning they offer a wealth of additional information.

The colliding neutron stars were smaller than the black holes that LIGO previously detected.

Black holes are so dense that not even photons of light can escape their gravity. Neutron stars are relatively small, about the size of a city, the compact remains of a larger star that died.

The National Science Foundation, an independent agency of the U.S. government, provided about $1.1 billion in funding for the LIGO research over 40 years.

 

(Reporting by Scott Malone; Editing by Peter Cooney)