Teenagers Edge Scientists to Make a Rare Pulsar Discovery
A couple of high school students edged past astronomers and cosmologist when they discovered a unique a neutron star binary.
As high school students in 2012, Cecilia McGough, and De'Shang Ray were part of an NSF-funded summer Pulsar Search Collaboratory workshop that required them to spot pulsars (spinning neutron stars that emit radio waves) from data produced by Robert C. Byrd Green Bank Radio Telescope. The pulsar has been designated PSR J1930-1852.
The system is unique because the pulsar has an orbit of 52 million kilometres around its companion neutron star, the largest ever known for such a system.
"Its orbit is more than twice as large as that of any previously known double neutron star system. The pulsar's parameters give us valuable clues about how a system like this could have formed. Discoveries of outlier systems like J1930-1852 give us a clearer picture of the full range of possibilities in binary evolution," said Joe Swiggum, lead author of the paper describing the discovery in the Astrophysical Journal.
The finding is also rare as only 10 percent of pulsar binaries involve a neutron star, with rest involving white dwarfs. The smaller number of neutron stars is due to the nature of supernova explosion. Following a supernova, the remnant neutron star is pushed away from the explosion due impact of explosion, making it difficult for two such neutron stars to cohabit in a gravitational embrace.
In the case of PSR J1930-1852, optical observations did not reveal any signs of a companion star which could be seen if the partner were a white dwarf or an active sun like star. This led scientists to conclude that the pulsar companion was a neutron star.
