Rare 'black widow' binary star with shortest orbit ever identified
Rare 'black widow' binary star with shortest orbit ever identified
Published 7th May, 2022
Context
Scientists have discovered a rare "triple black widow" system -- a pair of stars that rapidly circle each other before one is consumed by the other -- located some 3,000 light-years away.
About
About new discovery:
A black widow binary is a unique system that consists of a pulsar that is circling and slowly consuming a smaller companion star.
Astronauts have previously identified about two dozen black widow binaries in the Milky Way galaxy but the newest candidate has the shortest orbital period yet identified.
Named ZTF J1406+1222, the system has a pulsar and a companion star that circle each other every 62 minutes.
The system derives its name from the "black widow" spiders, in which the female eats the male after mating.
Another thing that makes the system unique apart from the short orbital period is the fact that it seems to host a third far-flung star that orbits the other two every 10,000 years.
The study used HiPERCAM, a high-speed camera developed by researchers at the University of Sheffield that can take more than 1,000 optical images per second, to find the exotic triple black widow.
Pulsars:
Pulsars are rapidly spinning neutron stars that are the collapsed cores of massive stars.
They have an incredibly fast rotational period, spinning around every few milliseconds and emitting flashes of high energy gamma and X-rays while doing so.
Typically, pulsars spin down and die quickly as they burn huge amounts of energy in a short amount of time.
But every once in a while, a passing star can ‘refuel’ them.
As a star nears a pulsar, the latter’s gravity pulls material off the star, providing new energy to spin the pulsar back up.
This ‘reignited’ pulsar then starts reradiating energy that strips the star further until it is completely destroyed.
Every black widow binary discovered to date was detected due to the gamma and X-ray flashes from the pulsar.
But for this system, Burdge came upon it through the optical flashing of the companion star.