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


Scientists discover how supermassive black holes keep galaxies turned off
An international team of scientists has identified a common phenomenon in galaxies that could explain why huge numbers of them turn into cosmic graveyards.

Supermassive black holes in 'red geyser' galaxies cause galactic warming
An international team of scientists, including the University of Kentucky's Renbin Yan, have uncovered a new class of galaxies, called "red geysers," with supermassive black hole winds so hot and energetic that stars can't form.

Supermassive black hole wind can stop new stars from forming
Scientists have uncovered a new class of galaxies with supermassive black hole winds that are energetic enough to suppress future star formation.

Hubble finds clues to the birth of supermassive black holes
Astrophysicists have taken a major step forward in understanding how supermassive black holes formed. Using data from Hubble and two other space telescopes, Italian researchers have found the best evidence yet for the seeds that ultimately grow into these cosmic giants.

NASA scientist suggests possible link between primordial black holes and dark matter
Dark matter is a mysterious substance composing most of the material universe, now widely thought to be some form of massive exotic particle.

Astrophysicists from the IAC discover an intense wind in the neighborhood of a black hole
V404 Cygni is a black hole within a binary system located in the constellation of Cygnus. In such systems, of which less than 50 are known, a black hole of around 10 times the mass of the Sun is swallowing material from a very nearby star, its companion star.

Hubble spies a spiral snowflake
Together with irregular galaxies, spiral galaxies make up approximately 60 percent of the galaxies in the local universe.

Intense wind found in the neighborhood of a black hole
An international team of astrophysicists, including Professor Phil Charles from the University of Southampton, have detected an intense wind from one of the closest known black holes to the Earth.

UCI astronomers determine precise mass of a giant black hole
Astronomers from the University of California, Irvine and other universities have derived a highly precise measurement of the mass of a black hole at the center of a nearby giant elliptical galaxy.

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.
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)


The contentious history of the idea of the black hole—the most fascinating and bizarre celestial object in the heavens

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...

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: A Very Short Introduction (Very Short Introductions)

Black Holes: A Very Short Introduction (Very Short Introductions)
by Katherine Blundell (Author)


Black holes are a constant source of fascination to many due to their mysterious nature. This Very Short Introduction, addresses a variety of questions, including what a black hole actually is, how they are characterized and discovered, and what would happen if you came too close to one.

Professor Katherine Blundell looks at the seemingly paradoxical, mysterious, and intriguing phenomena of black holes. Outlining their nature and characteristics, both those resulting from the spectacular collapse of heavy stars, and the giant black holes found at the centres of galaxies, she separates scientific fact from science fiction, and demonstrates the important role they play in the cosmos.

ABOUT THE SERIES:
The Very Short Introductions series from Oxford University Press contains...

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.

...

Black Holes: Everything You Need to Know About Black Holes and Black Hole Physics (space exploration, space, astronomy, Cosmology)

Black Holes: Everything You Need to Know About Black Holes and Black Hole Physics (space exploration, space, astronomy, Cosmology)



Everything you Need to Know about Black Holes and Black Hole Physics!

Black Holes have been, and are still to this day, one of the great mysteries of cosmology. They have inspired the imaginations of generations when looking out into space and have been the focus of astronomy for years. Today, much is known about black hole physics and the characteristics of these great beasts of space. This book will bring you up to speed with what we know today about black holes.


Here Is A Preview Of What You'll Learn...Black Hole FundamentalsBlack Hole HistoryBlack Hole FormationBlack Hole AnatomyEvent HorizonSpace and TimeEntering a Black HoleCosmology and AstronomySchwarzschild RadiusPrimordial Black HoleSupermassive Black HoleStellar Black HoleSingularityPhoton...

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...

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 Holes and Baby Universes and Other Essays

Black Holes and Baby Universes and Other Essays
by Stephen W. Hawking (Author)


NEW YORK TIMES BESTSELLER

THIRTEEN EXTRAORDINARY ESSAYS SHED NEW LIGHT ON THE MYSTERIES OF THE UNIVERSE—AND ON ONE OF THE MOST BRILLIANT THINKERS OF OUR TIME.
 
In his phenomenal bestseller A Brief History of Time, Stephen Hawking literally transformed the way we think about physics, the universe, reality itself. In these thirteen essays and one remarkable extended interview, the man widely regarded as the most brilliant theoretical physicist since Einstein returns to reveal an amazing array of possibilities for understanding our universe.

Building on his earlier work, Hawking discusses imaginary time, how black holes can give birth to baby universes, and scientists’ efforts to find a complete unified theory that would predict everything in the universe. With his...

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