In the news this morning ...
"Eclipsing Pulsar Promises Clues to Crushed Matter":
http://www.physorg.com/news201276630.html
"Astronomers using NASA's Rossi X-ray Timing Explorer (RXTE) have found the first fast X-ray pulsar to be eclipsed by its companion star."
"This is the first time we've detected X-ray eclipses from a fast pulsar that is also accreting gas," Markwardt said. "Using this information, we now know the size and mass of the companion star with unprecedented accuracy."
"It's difficult to establish precise masses for neutron stars, especially toward the higher end of the mass range theory predicts," said Craig Markwardt at NASA's Goddard Space Flight Center in Greenbelt. "As a result, we don't know their internal structure or sizes as well as we'd like. This system takes us a step closer to narrowing that down."
"The pulsar's powerful magnetic field directs infalling gas onto the star's magnetic poles. This means that the energy release occurs in hot spots that rotate with the neutron star, producing fast X-ray pulses. How fast? J1749 is spinning 518 times a second -- a city-sized sphere rotating as fast as the blades of a kitchen blender."
"We need to detect the normal star in the system with optical or infrared telescopes," Strohmayer said. "Then we can measure its motion and extract the same information about the pulsar that the pulsar's motion told us about the star."
Very interesting ....
Cheers
