Posted: April 7th, 2013 | Author: Marcus Dangerfield | Filed under: Cankler Science News | Tags: black hole, brown dwarf, European Space Agency INTEGRAL, NGC 4845 Galaxy, University of Geneva | Comments Off
Swiss astrophysicists have witnessed the most rare of event, a black hole awakening from its slumber to devour a planet-sized object in a galaxy 47 million light years away. Observers from the University of Geneva using the European Space Agency’s INTEGRAL satellite project, revealed a black hole that had been slumbering for years chomping on a giant, low-mass object that had ventured too close.
Scientists at the Swiss university analyse the data collected by INTEGRAL, launched in 2002 to study gamma rays and shed light on events far from Earth’s galaxy. They spotted a light flare coming from a black hole in the centre of the NGC 4845 galaxy, which has a mass more than 300,000 times greater than the Sun and had been dormant for more than 30 years, the university said in a statement.
Matter-sucking black holes normally lurk dormant and undetected at the centre of galaxies, but can occasionally be tracked by the scraps left over from their stellar feasts. This black hole had woken up and absorbed an object with a mass 15 times that of Jupiter after taking three months to drag the snack from its trajectory. It managed to swallow 10 per cent of the object’s total mass, while the remainder stayed in orbit :: Read the full article »»»»
Posted: August 4th, 2012 | Author: Michael Courtenay | Filed under: Astronomy, Cankler Science News | Tags: black hole, Dying Star, European Space Agency, NASA, Swift Gamma Ray Burst Telescope, University of Michigan | Comments Off
For the first time astronomers have detected the last gasps of a star being torn apart by – a previously dormant – giant black hole. The signals, which came from a galaxy 3.9 billion light years away, were x-rays generated by matter heated to millions of degrees and torn apart as material from the star crosses the black hole’s event horizon.
Known as quasi-periodic oscillations, they are a characteristic feature of stellar black holes, which have about 10 times the mass of the Sun. Dr Rubens Reis from the University of Michigan is the lead author of the paper published today in the journal Science.
Dr Reis says the findings confirm the constancy of black hole physics. ”This is telling us that the same physical phenomenon we observe in stellar mass black holes is also happening in black holes a million times the mass of the Sun, and in black holes that were previously asleep,” he said.
Dr Reis and colleagues first detected the event with NASA’s Swift Gamma Ray Burst Telescope last year, but did not pick up the oscillations at that time. The blips in the signals were detected in follow-up observations using the joint Japanese-NASA Suzaku and the European Space Agency ZMM-Newton orbiting X-ray observatories.
“You can think of it as hearing the star scream as it gets devoured,” said University of Michigan astronomy professor Jon Miller, who co-authored the paper.
The oscillating signal repeats at a characteristic frequency, which would sound like an ultra-low D sharp. The oscillations were occurring once every 200 seconds, meaning the stellar material was orbiting less than 9.3 million kilometres from the centre of the black hole. Professor Miller said that the discovery opens the possibility of studying orbits close to black holes, but that are extremely distant from earth.
Posted: December 5th, 2011 | Author: M.Aaron Silverman | Filed under: Applied Science, Quantum Mechanics, Quantum Physics | Tags: black hole, Dark Matter, Hubble Space Telescope, NASA, Quantum Mechanics | Comments Off
Scientists have discovered the two biggest black holes ever observed, each with a mass billions of times greater than the Sun’s, according to a study published overnight. The two giants are located in the heart of a pair of galaxies several hundred million light years from Earth, the study was published in the scientific journal Nature.
Each black hole is estimated to have a mass about 10 billion times greater than the sun, dwarfing the previously largest-known black hole, which has a mass of 6.3 billion suns. The University of California, Berkeley, team led by Nicholas McConnell and Chung-Pei Ma said one black hole is located in NGC 3842, the brightest of a cluster of galaxies about 320 million light years from Earth. The second hole is of “comparable or greater mass” and is located in NGC 4889, the brightest galaxy in the Coma cluster, about 335 million light years away.
“These two black holes are significantly more massive than predicted,” the astronomers wrote.
The researchers said their calculations suggest that different evolutionary processes influence the growth of the largest galaxies and their black holes than in smaller galaxies. Astronomers have long supposed that since the universe began it has harboured black holes with a mass the size of the two newly found giants. These cosmic gluttons grow in tandem with their galaxies, slurping up gases, planets and stars :: Read the full article »»»»