Astronomers know of about two dozen binary images of a black widow in the Milky Way.
Astronomers know of about two dozen binary images of a black widow in the Milky Way.
Scientists have discovered a rare “triple black widow” system – a pair of stars that rapidly revolve around each other before one is swallowed by the other – located about 3,000 light-years away.
The stellar system, called “ZTF J1406 + 1222”, has the shortest known orbit of any binary black widow, i.e. 62 minutes, according to researchers.
What makes this system unique is that it contains a third star that orbits the central pair every 10,000 years, according to a finding published in the journal Nature on May 4.
A team led by scientists at the Massachusetts Institute of Technology (MIT) in the United States has discovered a stellar oddity that appears to be a new binary black widow – a fast-spinning neutron star or pulsar that orbits and slowly swallows a smaller companion star.
The system gets its name from the “black widow” spiders, in which the female eats the male after mating.
Astronomers know of about two dozen binary images of a black widow in the Milky Way.
The study, which includes astronomers at the University of Sheffield in the United Kingdom, suggests that the ZTF J1406 + 1222 has the shortest orbital period ever identified, with the pulsar and companion star orbiting each other every 62 minutes.
The study uses HiPERCAM, a high-speed camera developed by researchers at the University of Sheffield that can produce more than 1,000 optical images per second to detect the exotic triple black widow.
The discovery raised questions about how such a system could have formed, with researchers speculating that, as with most black widow binary systems, the triple system may have originated from a dense constellation of old stars known as a globular cluster.
This particular cluster may have landed in the center of the Milky Way, where the gravity of the central black hole was enough to break the cluster, leaving the triple black widow intact.
With the help of HiPERCAM, the research team uses a new approach to discovering the triple system. Although most of the black widow’s binaries were initially detected by radio and gamma radiation from the central pulsar, the team used visible light, particularly different light from the accompanying binary star, to detect ZTF J1406 + 1222.
“Thanks to the extreme sensitivity of Sheffield’s HiPERCAM camera, we have discovered the most extreme member of the black widow class of binary stars, along with a promising new method for detecting such systems,” said Professor Vic Dylan, co-author of the study. in Physics and Astronomy, University of Sheffield.
The Black Widow’s binary systems are powered by pulsars, fast-spinning neutron stars that are collapsed massive star cores.
Pulsars have a dizzying period of rotation, rotating every few milliseconds and emitting flashes of radio and high-energy gamma rays in the process.
Pulsars usually spin down and die quickly as they burn a huge amount of energy, but an occasional passing star can give new life to the pulsar.
As a star approaches, the pulsar’s gravity pulls material from the star, providing new energy to turn the pulsar back. The “recycled” pulsar then begins to emit energy, which further degrades the star and eventually destroys it.
Astronomers have found that the day side of the accompanying star – the side that is constantly facing the pulsar – can be many times hotter than its night side, due to the constant high-energy radiation it receives from the pulsar.
This allowed them to find the new black widow by looking for the accompanying star instead of looking for the pulsar directly.
The new method could make it easier to detect black widows in the future, as a star whose brightness changes periodically with huge numbers is a strong signal that it is a binary with a pulsar, according to a study supported by the National Science Foundation.
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