This brings the total number of pulsars there to 25 and drives home the fact that our neighboring galaxy has a much higher concentration of pulsars than we do, perhaps created during a burst of star formation a few million years ago when the two galaxies were at their closest. Silas Laycock a graduate student at the University of Southampton, England, together with a team at NASA's Goddard Space Flight Center, Greenbelt, Md., led by Dr. Robin Corbet, uncovered the pulsars with the Rossi X-ray Timing Explorer satellite. Laycock presented the team's findings Wednesday at the Gamma Ray 2001 meeting in Baltimore. This image shows the positions of the known X-ray pulsars in the Small Magellanic Cloud. The SMC is shown as it appears in a radio map which traces the extent of the cool hydrogen gas that fills this tiny galaxy.
Yellow stars mark the approximate positions of the new pulsars.
A few years ago we only knew of one pulsar in the Small Magellanic Cloud. Now we are at 25 and still climbing. An X-ray pulsar is a type of spinning neutron star, the core remains of a star once several times more massive than our sun. Such a massive star, upon depleting its nuclear fuel, violently expels much of its mass into space in an event called a supernova explosion. The ember, which still packs more than a sun's worth of mass into a sphere about 10 miles wide, becomes the neutron star.