Welcome to the Rossi X-ray Timing Explorer Learning Center!


The Rossi X-ray Timing Explorer (RXTE) is a satellite that observes the fast-moving, high-energy worlds of black holes, neutron stars, X-ray pulsars and bursts of X-rays that light up the sky and then disappear forever.

How fast and how energetic are they? Well, some pulsars spin faster than a thousand times a second. And a neutron star produces a gravitational pull so powerful that a marshmallow striking the star's surface would hit with the force of an early atomic bomb. Astronomers study changes that happen from microseconds to months in cosmic objects to learn about how gravity works near black holes, how pulsars in binary systems are affected by mass transferring from one star to the other, and how the giant engines in distant galaxies are powered. RXTE was launched into low-Earthe orbit on December 30, 1995. It spent over 16 years making unique contributions to our understanding of these extreme objects.


For RXTE, the trick to observing these kinds of objects is all in the timing -- an ability to observe changes in X-ray brightness that occur in a mere thousandths of a second, or over several years.

Learn more about how this one-of-a-kind satellite has reshaped our understanding of what goes on in the most violent and bizarre regions of the Universe.

About Our Site

RXTE Learning Center was begun in the summer of 1995 and several teacher interns contributed content from 1997-1999. (See also: Meet the RXTE Learning Center Team) We are pleased to present an updated website in 2011.