迄今发现拥有最宽运行轨道的脉冲星

A team of highly determined high school students discovered a never-before-seen pulsar by painstakingly analyzing data from the National Science Foundation's (NSF) Robert C. Byrd Green Bank Telescope (GBT). Further observations by astronomers using the GBT revealed that this pulsar has the widest orbit of any around a neutron star and is part of only a handful of double neutron star systems. This impressive find will help astronomers better understand how binary neutron star systems form and evolve.

Pulsars are rapidly spinning neutron stars, the superdense remains of massive stars that have exploded as supernovas. As a pulsar spins, lighthouse-like beams of radio waves, streaming from the poles of its powerful magnetic field, sweep through space. When one of these beams sweeps across Earth, radio telescopes can capture the pulse of radio waves.

"Pulsars are some of the most extreme objects in the universe," said Joe Swiggum, a graduate student in physics and astronomy at West Virginia University in Morgantown and lead author on a paper accepted for publication in the Astrophysical Journal explaining this result and its implications. "The students' discovery shows one of these objects in a really unique set of circumstances."

About 10 percent of known pulsars are in binary systems; the vast majority of these are found orbiting ancient white dwarf companion stars. Only a rare few orbit other neutron stars or main sequence stars like our Sun. The reason for this paucity of double neutron star systems, astronomers believe, is the process by which pulsars and all neutron stars form.

When a massive star goes supernova at the end of its normal life, the explosion can be a little one-sided, imparting a "kick" to the remaining stellar core. When this happens, the resulting neutron star is sent hurtling through space. These kicks -- and the corresponding mass loss from a supernova explosion -- mean that the chances of two such stars remaining gravitationally locked in the same system are remarkably slim.

This pulsar, which received the official designation PSR J1930-1852, was discovered in 2012 by Cecilia McGough, who was a student at Strasburg High School in Virginia at the time, and De'Shang Ray, who was a student at Paul Laurence Dunbar High School in Baltimore, Maryland.

These students were participating in a summer Pulsar Search Collaboratory (PSC) workshop, which is an NSF-funded educational outreach program that involves interested high school students in analyzing pulsar survey data collected by the GBT. Students often spend weeks and months poring over data plots, searching for the unique signature that identifies a pulsar. Those who identify strong pulsar candidates are invited to Green Bank to work with astronomers to confirm their discovery.