Science Current Events | Science News | Brightsurf.com
 

Black hole caught red-handed in stellar homicide

May 03, 2012

Astronomers have gathered the most direct evidence yet of a supermassive black hole shredding a star that wandered too close.

Supermassive black holes, weighing millions to billions times more than the sun, lurk in the centers of most galaxies. These hefty monsters lay quietly until an unsuspecting victim, such as a star, wanders close enough to get ripped apart by their powerful gravitational clutches.

Astronomers have spotted these stellar homicides before, but this is the first time they can identify the victim. Using a slew of ground- and space-based telescopes, a team of astronomers led by Suvi Gezari of The Johns Hopkins University has identified the victim as a star rich in helium gas. The star resided in a galaxy 2.7 billion light-years away.

Her team's results will appear in the May 3 online edition of the journal Nature.

"When the star is ripped apart by the gravitational forces of the black hole, some part of the star's remains falls into the black hole, while the rest is ejected at high speeds. We are seeing the glow from the stellar gas falling into the black hole over time," said Gezari, an associate research scientist in the Henry A. Rowland Department of Physics and Astronomy at Johns Hopkins' Krieger School of Arts and Sciences. "We're also witnessing the spectral signature of the ejected gas, which we find to be mostly helium. It is like we are gathering evidence from a crime scene.

Because there is very little hydrogen and mostly helium in the gas we detect from the carnage, we know that the slaughtered star had to have been the helium-rich core of a stripped star."

This observation yields insights about the harsh environment around black holes and the types of stars swirling around them.

This is not the first time the unlucky star had a brush with the behemoth black hole. Gezari and her team think the hydrogen-filled envelope surrounding the star's core was lifted off a long time ago by the same black hole. The star may have been near the end of its life. After consuming most of its hydrogen fuel, it had probably ballooned in size, becoming a red giant. The astronomers think the bloated star was looping around the black hole in a highly elliptical orbit, similar to a comet's elongated orbit around the sun. On one of its close approaches, the star was stripped of its puffed-up atmosphere by the black hole's powerful gravity. The stellar remains continued its journey around the center, until it ventured even closer to the black hole to face its ultimate demise and was completely disrupted.

Astronomers have predicted that stripped stars circle the central black hole of our Milky Way galaxy, Gezari pointed out. These close encounters, however, are rare, occurring roughly every 100,000 years. To find this one event, Gezari's team monitored hundreds of thousands of galaxies in ultraviolet light with the Galaxy Evolution Explorer (GALEX), a space-based observatory, and in visible light with the Pan-STARRS1 telescope on Mount Haleakala, Hawaii. Pan-STARRS, short for Panoramic Survey Telescope and Rapid Response System, scans the entire night sky for all kinds of transient phenomena, including supernovae. The team was looking for a bright flare in ultraviolet light from the nucleus of a galaxy with a previously dormant black hole.

In June 2010, they spotted one with both telescopes. Both continued to monitor the flare as it reached peak brightness a month later, and then slowly began to fade over the next 12 months. The brightening event was similar to that of a supernova, but the rise to the peak was much slower, taking nearly one and a half months.

"The longer the event lasted, the more excited we got, since we realized that this is either a very unusual supernova or an entirely different type of event, such as a star being ripped apart by a black hole," said team member Armin Rest of the Space Telescope Science Institute in Baltimore.

By measuring the increase in brightness, the astronomers calculated the black hole's mass at roughly 3 million suns, which equals the weight of our Milky Way's black hole.

Spectroscopic observations with the MMT Observatory on Mount Hopkins in Arizona showed that the black hole was swallowing lots of helium. Spectroscopy divides light into its rainbow colors, which yields an object's characteristics, such as its temperature and gaseous makeup.

"The glowing helium was a tracer for an extraordinarily hot accretion event," Gezari said. "So that set off an alarm for us. And the fact that no hydrogen was found set off a big alarm that this was not typical gas. You can't find gas like that lying around near the center of a galaxy. It's processed gas that has to have come from a stellar core. There's nothing about this event that could be easily explained by any other phenomenon."

The observed speed of the gas also linked the material to a black hole's gravitational pull. MMT measurements revealed that the gas was moving at more than 20 million miles an hour (over 32 million kilometers an hour). However, measurements of the speed of gas in the interstellar medium reveal velocities of only about 224,000 miles an hour (360,000 kilometers an hour).

"The place we also see these kinds of velocities are in supernova explosions," Rest said. "But the fact that it is still shining in ultraviolet light is incompatible with any supernova we know."

To completely rule out the possibility of an active nucleus flaring up in the galaxy, the team used NASA's Chandra X-ray Observatory to study the hot gas. Chandra showed that the characteristics of the gas didn't match those from an active galactic nucleus.

"This is the first time where we have so many pieces of evidence, and now we can put them all together to weigh the perpetrator (the black hole) and determine the identity of the unlucky star that fell victim to it," Gezari said. "These observations also give us clues on what evidence to look for in the future to find this type of event."

Johns Hopkins University


Related Black Hole Current Events and Black Hole News Articles


NASA's Fermi Telescope helps link cosmic neutrino to blazar blast
Nearly 10 billion years ago, the black hole at the center of a galaxy known as PKS B1424-418 produced a powerful outburst. Light from this blast began arriving at Earth in 2012.

NASA's Fermi telescope poised to pin down gravitational wave sources
On Sept. 14, waves of energy traveling for more than a billion years gently rattled space-time in the vicinity of Earth.

Supermassive black holes may be lurking everywhere in the universe
A near-record supermassive black hole discovered in a sparse area of the local universe indicates that these monster objects - this one equal to 17 billion suns - may be more common than once thought, according to University of California, Berkeley, astronomers.

Behemoth black hole found in an unlikely place
Astronomers have uncovered one of the biggest supermassive black holes, with the mass of 17 billion Suns, in an unlikely place: the centre of a galaxy that lies in a quiet backwater of the Universe.

Gravitational wave search provides insights into galaxy evolution and mergers
New results from NANOGrav - the North American Nanohertz Observatory for Gravitational Waves - establish astrophysically significant limits in the search for low-frequency gravitational waves.

Fast radio burst 'afterglow' was actually a flickering black hole
Last February a team of astronomers reported detecting an afterglow from a mysterious event called a fast radio burst, which would pinpoint the precise position of the burst's origin, a longstanding goal in studies of these mysterious events.

Earth-space telescope system produces hot surprise
Astronomers using an orbiting radio telescope in conjunction with four ground-based radio telescopes have achieved the highest resolution, or ability to discern fine detail, of any astronomical observation ever made.

York University astrophysicists detect ultra-fast winds near supermassive black hole
New research led by astrophysicists at York University has revealed the fastest winds ever seen at ultraviolet wavelengths near a supermassive black hole.

The center of the Milky Way
Researchers have been mapping the centre of our galaxy in very-high-energy gamma rays using these telescopes - the most sensitive of their kind - for over 10 years.

Record-breaking ultraviolet winds discovered near black hole
The fastest winds ever seen at ultraviolet wavelengths have been discovered near a supermassive black hole by a research team that includes a Penn State University astronomer.
More Black Hole Current Events and Black Hole News Articles

Black Hole (Pantheon Graphic Novels)

Black Hole (Pantheon Graphic Novels)
by Charles Burns (Author)


Winner of the Eisner, Harvey, and Ignatz Awards

The setting: suburban Seattle, the mid-1970s. We learn from the outset that a strange plague has descended upon the area’s teenagers, transmitted by sexual contact. The disease is manifested in any number of ways — from the hideously grotesque to the subtle (and concealable) — but once you’ve got it, that’s it. There’s no turning back.

As we inhabit the heads of several key characters — some kids who have it, some who don’t, some who are about to get it — what unfolds isn’t the expected battle to fight the plague, or bring heightened awareness to it , or even to treat it. What we become witness to instead is a fascinating and eerie portrait of the nature of high school alienation itself — the savagery,...

Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved

Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved
by Marcia Bartusiak (Author)


For more than half a century, physicists and astronomers engaged in heated dispute over the possibility of black holes in the universe. The weirdly alien notion of a space-time abyss from which nothing escapes—not even light—seemed to confound all logic. This engrossing book tells the story of the fierce black hole debates and the contributions of Einstein and Hawking and other leading thinkers who completely altered our view of the universe.

Renowned science writer Marcia Bartusiak shows how the black hole helped revive Einstein’s greatest achievement, the general theory of relativity, after decades during which it had been pushed into the shadows. Not until astronomers discovered such surprising new phenomena as neutron stars and black holes did the once-sedate universe...

Black Hole Blues and Other Songs from Outer Space

Black Hole Blues and Other Songs from Outer Space
by Janna Levin (Author)


The authoritative story of the headline-making discovery of gravitational waves—by an eminent theoretical astrophysicist and award-winning writer.


From the author of How the Universe Got Its Spots and A Madman Dreams of Turing Machines, the epic story of the scientific campaign to record the soundtrack of our universe.
 
Black holes are dark. That is their essence. When black holes collide, they will do so unilluminated. Yet the black hole collision is an event more powerful than any since the origin of the universe. The profusion of energy will emanate as waves in the shape of spacetime: gravitational waves. No telescope will ever record the event; instead, the only evidence would be the sound of spacetime ringing. In 1916, Einstein predicted the existence of...

The Black Hole: Book One of The Shadow Order: A Space Opera

The Black Hole: Book One of The Shadow Order: A Space Opera
by Phalanx Press


Seb Zodo lives on the dusty planet of Danu. He’s an unemployed dropout who makes his money fighting in bars and taking a cut of the winnings from the touts.

Having never lost a fight, Seb is addicted to the adrenaline of the duel. So when he makes a promise to leave brawling behind, his world’s turned on its head. Especially when he finds himself with no money on a hostile planet where the fighting pits offer more than Seb has ever won before.

Trapped and with no way out, Seb must decide whether to fight or not.

Every decision he makes with his fists seems to throw his life into deeper chaos, but he’s already hit rock bottom.

With the smell of blood and sweat from the fighting pits in his nostrils, Seb watches the current...

Death by Black Hole: And Other Cosmic Quandaries

Death by Black Hole: And Other Cosmic Quandaries
by Neil deGrasse Tyson (Author)


“[Tyson] tackles a great range of subjects . . . with great humor, humility, and―most important― humanity.” ―Entertainment Weekly Loyal readers of the monthly "Universe" essays in Natural History magazine have long recognized Neil deGrasse Tyson's talent for guiding them through the mysteries of the cosmos with clarity and enthusiasm. Bringing together more than forty of Tyson's favorite essays, ?Death by Black Hole? explores a myriad of cosmic topics, from what it would be like to be inside a black hole to the movie industry's feeble efforts to get its night skies right. One of America's best-known astrophysicists, Tyson is a natural teacher who simplifies the complexities of astrophysics while sharing his infectious fascination for our...

Black Holes and Time Warps: Einstein's Outrageous Legacy (Commonwealth Fund Book Program)

Black Holes and Time Warps: Einstein's Outrageous Legacy (Commonwealth Fund Book Program)
by Kip S. Thorne (Author), Stephen Hawking (Foreword)


Ever since Albert Einstein's general theory of relativity burst upon the world in 1915 some of the most brilliant minds of our century have sought to decipher the mysteries bequeathed by that theory, a legacy so unthinkable in some respects that even Einstein himself rejected them. Which of these bizarre phenomena, if any, can really exist in our universe? Black holes, down which anything can fall but from which nothing can return; wormholes, short spacewarps connecting regions of the cosmos; singularities, where space and time are so violently warped that time ceases to exist and space becomes a kind of foam; gravitational waves, which carry symphonic accounts of collisions of black holes billions of years ago; and time machines, for traveling backward and forward in time.

...

Seven Brief Lessons on Physics

Seven Brief Lessons on Physics
by Carlo Rovelli (Author)


Instant New York Times Bestseller

“Short and resonant. . . . The essays in Seven Brief Lessons on Physics arrive like shots of espresso.”—The New York Times

“A startling and illustrative distillation of centuries of science.”—The Economist
 
“Lean, lucid and enchanting.”—New Scientist
 
The international bestseller that reveals all the beauty of modern physics in seven short and enlightening lessons
 
Seven Brief Lessons on Physics is a book about the joy of discovery. Carlo Rovelli brings a playful, entertaining, and mind-bending introduction to modern physics, offering surprising—and surprisingly easy to grasp—explanations of Einstein's general relativity, quantum mechanics, elementary particles, gravity, black holes, the...

Black Holes (True Books: Space (Paperback))

Black Holes (True Books: Space (Paperback))
by Ker Than (Author)


- Clean new design for easy readability and comprehension
- Updated text presented in a lively, continuous narrative
- New center-spread "sidebar" feature presenting material in a fun, creative way
- Excellent age-appropriate introduction to curriculum-relevant subjects
- "Important Words" glossary clarifies subject-specific vocabulary
- "Resources" section encourages independent study
- Index makes navigating subject matter easy

Black Hole: A Novel

Black Hole: A Novel
by Bucky Sinister (Author)


There are no old drug addicts. That's what everyone says, at least. So how did Chuck get to his forty-third birthday and find himself still neck-deep in this scene? He knows he's the creepy old guy with the drugs or the guy who's too old to be at the party doing everyone else's drugs, but if it ain't broke ... Well, he manages to make it to work at the dwarf whale distributor every day. He may hate that his dearly seedy San Francisco has become overrun with Starbucks, startups, and Lululemon moms, but he makes do every month for the rent-controlled apartment he shares with roommates he never sees. It's not perfect, but it's livable.

In the end, though, every addict has that one special vice that can tip them from relatively functional to completely unhinged. For Chuck, it's a new...

A Black Hole Is Not a Hole

A Black Hole Is Not a Hole
by Carolyn Cinami DeCristofano (Author), Michael Carroll (Illustrator)


Get ready to S-T-R-E-T-C-H your mind!

What is a black hole? Where do they come from? How were they discovered? Can we visit one? Carolyn Cinami DeCristofano takes readers on a ride through the galaxies (ours, and others), answering these questions and many more about the phenomenon known as a black hole.

In lively and often humorous text, the book starts off with a thorough explanation of gravity and the role it plays in the formation of black holes. Paintings by Michael Carroll, coupled with real telescopic images, help readers visualize the facts and ideas presented in the text, such as how light bends, and what a supernova looks like.

A BLACK HOLE IS NOT A HOLE is an excellent introduction to an extremely complex scientific concept. Back matter includes a timeline...

© 2016 BrightSurf.com