Texas Tech Astrophysicist Among Group to Discover Brightest Pulsar Ever Recorded
That told us this was actually a pulsar – a star with about the mass of the sun packed into a region about the size of a city." - Tom Maccarone
A group of researchers have discovered the brightest pulsar ever recorded with a Texas Tech astrophysicist among their number.
A pulsar is a type of neutron star. According to NASA’s Goddard Space Flight Center, they are the remnants of imploded star cores left over after a supernova explosion of star. The newly discovered pulsar reportedly burns with the same light intensity of approximately 10 million of Earth’s suns.
The quality that makes pulsars most unique is their pulses of radiation. Pulsars send out a constant stream of radiation, but due to differences between the star’s rotation and magnetic axes and our vantage point on earth, the radiation stream seems to pulse at a regular interval. A common analogy used to demonstrate this concept is the sweeping beam of a light house.
Some groups actually advocate the use of an ideal pulsar to tell time, much like the cesium atom used in atomic clocks.
The new pulsar was discovered in Galaxy M82 12 million light-years away by researchers utilizing NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR. The finding was first published in the October 9 edition of the peer-reviewed journal, Nature. NuSTAR is led by the California Institute of Technology and managed by NASA’s jet propulsion laboratory, both in Pasadena, California.
Associate Professor of Physics at Texas Tech, Tom Maccarone, co-authored the paper and said that the team was originally observing a supernova in the galaxy but ended up uncovering part of the mystery behind the source of exceedingly rare, ultraluminous X-rays.
For years, scientists believed the ultra-rare, ultraluminous X-ray sources were caused by black holes eating other nearby stars, accreting gas and emitting a light that’s millions of times brighter than our sun.That may still be the case with most. However, we discovered that one of these entities, of which there are about 20 known so far, is actually a pulsar.”
Maccarone’s co-author, Matteo Bachetti of the University of Toulouse in France, said scientist have been assuming the ultraluminous radiation came from black holes of which pulsars are very similar.
Scientist are puzzled as to why this dead star can generate such luminous x-rays and are theorizing that it could be feeding off of nearby stars.
Jeanette Gladstone with the University of Alberta Canada, who was unaffiliated with the study, commented on the nature of ultraluminous x-ray radiation in a Texas Tech news release.
In the news recently, we have seen that another source of unusually bright X-rays in the M82 galaxy seems to be a medium-sized black hole. Now, we find that the second source of bright X-rays in M82 isn’t a black hole at all. This is going to challenge theorists and pave the way for a new understanding of the diversity of these fascinating objects.”
NASA’s Chandra X-ray Observatory and Swift Satellite were also monitoring galaxy M82 and confirmed the pulsar. Astronomers are now planning follow-up observations with NuSTAR, Swift and Chandra to further research the anomaly.