“Detecting the gravitational waves from the merger of two black holes by LIGO’s detectors for the second time is highly important”, said MSU physics department professor Valery Mitrofanov, adding that this underpins gravitational wave astronomy. The detected signal comes from the last 27 orbits of the black holes before their merger.
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With this second observation, “we are now a real observatory”, said Gabriela Gonzalez, LIGO spokesperson and professor of physics and astronomy at Louisiana State University, in a press conference at the annual meeting of the American Astronomical Society.
On merging, the two black holes formed a spinning black hole about 21 times the mass of the sun.
An global team of scientists has identified a second gravitational wave event in the data from the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO).
The collision took place 1.4 billion years ago in a small galaxy far, far away between a black hole eight times the mass of the sun and one 14 times the mass of the sun.
This follows their previous announcement, just four months ago, of the first ever detection of gravitational waves, also from a set of merging black holes.
Since the 1970 scientists had good circumstantial evidence of the existence of such waves, which were first described by Albert Einstein in 1916 in his General Theory of Relativity.
The news follows the breakthrough discovery of gravitational waves in February. The waves were measured 1.1 milliseconds apart by two LIGO detectors, and therefore provide only little hints about the direction.
The black holes were 14 and 8 times the mass of the sun. It reflects the energy converted into the gravitational waves, remember that mass and energy are related by E=mc.
“This second detection of gravitational waves tells us that black holes are much more common in the universe than previously believed and clearly come together in pairs, which we don’t completely understand”.
Now, it seems that black hole collisions may be frequent facts of nature, with humanity at least tuned in to the darker, deeper vibrations of nature.
The gravitational waves were detected at 10:38pm Eastern Time on December 25, 2015 (3:38am Coordinated Universal Time).
“Gravitational waves are our newest way to observe the universe”. This can help with a greater understanding of the origin and evolution of black holes.
Until gravitational waves were detected, almost all astronomy relied on electromagnetic observations – visible light, radio waves and X-rays.
Due to the large worldwide team analysing signals from two detectors, it took longer to write the paper than confirm the signal, Professor Ken Strain, who was involved in building the Advanced LIGO hardware told The Register.
They have continued to refine their model and make correlations between the size of the black holes that produce gravitational waves and the types of waves detected.
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The chair of the Australian Consortium for Interferometric Gravitational Astronomy, Dr Bram Slagmolen, says he’s proud of the contribution Australian scientists had made to the detection.
