Scientists may have observed something that has never been seen before: a black hole engulfing a neutron star.
About 900 million years ago, a catastrophic space event caused a ripple in space and time that passed through Earth last week (August 14). The scientists observed the event both in the advanced LIGO (Laser Interferometer Gravity Wave Observatory) and in Virgo, LIGO's Italian counterpart. After further investigation and initial speculation, scientists believe that this ripple could have been caused by the merging of a black hole and a neutron star.
Currently, scientists can only confirm that the signal detected by LIGO and Virgo is a candidate for gravity waves, LIGO team member Christopher Berry told Space.com. But while Berry hesitates to refer to the binary known as S1
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On September 14, 2015, about one hundred years after Albert Einstein predicted their existence, LIGO made the first discovery of gravity Now, just a few short years later, scientists are discovering gravitational waves with regularity, Berry said, but while this growth in gravitational-astronomy is an incredible achievement, it's still very difficult for researchers and it takes a long time to determine what
Previously, researchers discovered binary systems composed of two black holes and systems composed of two neutron stars. So far, however, there is no confirmed detection of a black neutron-hole star system. In this system, a black hole will eat at – or even potentially swallow an entire – neutron star.
Scientists currently believe that objects in these systems that are up to three times the mass of our sun are neutron stars, and objects that are at least five times larger than the mass of our sun, to be black holes. However, while scientists have not yet observed a black hole under five solar masses or a neutron star above about two and a half solar masses, they do not know what the minimum mass of a black hole is or what the maximum mass of a may be a neutron star.
So, while the smaller object in this most recently discovered binary unit is smaller than three solar masses, it may not be a neutron star. "If you want to bet, a neutron star is probably where you would like to invest your money," Berry said, suggesting that the smaller of the two objects is probably a neutron star. However, he added: "It is not yet certain and although I would say that it will probably be a neutron star, I just want to emphasize the uncertainty."
Objects may be a binary neutron star; that is, the fiery fusion between two neutron stars, which are collapsed nuclei of massive stars. It can also be a double double black hole. If, after all, this is a double black hole, it means that one of the black holes in the system will be smaller than three solar masses, and this will be the smallest black hole seen so far.
So, while it is fascinating for scientists to confirm that this is a fusion between a black hole and a neutron star, as it is something no one has seen before, any of these possible results would be a step forward in scientific research. As we study these systems, "we can learn a lot about the physics that goes into forming neutron stars and black holes, so this is another step toward completing our understanding of how these binary systems develop and form," Berry said.
To confirm what created the gravitational waves discovered by LIGO and Virgo, scientists will scan the area of the sky where the merger may have occurred and try to get more information about the event. Gravity-wave astronomers can also study slight distortions in the signal detected by LIGO and Virgo, but, as Berry mentioned, this method is very difficult.
"The ANU SkyMapper telescope responds to the detection signal and scans the entire probable region of space where the event occurred," said Susan Scott, a lecturer at the Australian National University for the School of Physics Research on the effort to confirm which objects may have merged. "We have not found any visual confirmation at this time.