A 'Jekyll And Hyde' Cosmic Mass Is Flipping Between Alter Egos
A cosmic mass nearly 20,000 years away has transitioned identities in just over a decade, despite the process usually taking billions of years.
Observations by NASA's Chandra X-ray Observatory and the National Science Foundation’s Karl F. Jansky Very Large Array (VLA) have found a double star system that's making rapid changes.
Located about 20,000 light-years away from Earth, the double (or binary) star system Terzan 5, is flipping between "alter egos", NASA said.
A binary star system has a neutron star -- created from the dense remains of a supernova explosion -- that is in close orbit around another star which has either the same or less mass than that of the Sun.
In this case, the heavier neutron is pulling material from the lower-mass star to create a disc.
"Astronomers can detect these so-called accretion discs by their bright X-ray light, and refer to these objects as 'low-mass X-ray binaries'," NASA said.
The neutron star increases its rotation rate as the material from the disc falls onto its surface, eventually rotating hundreds of times a second and growing to have more mass than the Sun.
Over time, the amount of matter collecting on the surface slows down before being dragged off by the magnetic field from the neutron star and becoming a millisecond pulsar.
"While scientists expect the complete evolution of a low-mass X-ray binary into a millisecond pulsar should happen over several billion years, there is a period of time when the system can switch rapidly between these two states," NASA said.
Incredibly, Terzan 5 has completed this transformation from a low-mass X-ray binary system to a millisecond pulsar and back again in just over a decade.
In 2003, data from Chandra showed Terzan 5 was acting as a low-mass X-ray binary system.
But between 2009 and 2014, Chandra data showed the system was acting like a millisecond pulsar.
"The amount of radio and X-ray emission and the corresponding spectra (the amount of emission at different wavelengths) agree with expectations for a millisecond pulsar," NASA said.
By 2016, Chandra Observatory said it was back to being a low-mass X-ray binary system again.
Researchers plan on studying the X-rays emitted by Terzan 5 further to confirm the 'Jekyll and Hyde' phenomenon.