ETA CARINAE

The most luminous star in our galaxy is dimmed by obscuring matter and by its great distance—7,000 light-years away. Eta Carinae, roughly 120 times as massive as the sun, is now practicing for an explosion that will tear it apart, probably creating a black hole. What you see in visible light (left) are two giant lobes of gas and stardust cast off by the unstable star, hidden within. The orange horseshoe in Chandra’s X-ray image (right) surrounds those visible lobes; it may be the remnant of an outburst that happened a millennium ago. The blue cloud and the white central dot consist of 60-million-degree gas shooting outward, perpendicular to the lobes, at millions of miles per hour. The white spot is around 100 times the size of Pluto’s orbit. The star itself lies buried deep inside it.

Image on left courtesy of NASA/HST/J. Morse/K. Davidson; right, courtesy of NASA/CXC/SAO


CRAB NEBULA

This tortured cloud is the remnant of a supernova explosion that was brilliantly visible in 1054. The predecessor star was a bit closer to us than Eta Carinae but far smaller. Instead of a black hole, it left behind a rotating neutron star, or pulsar, that spins 30 times a second and shoots beams of particles from its poles. The pulsar is the white central dot in this series of images, which Chandra took over several months. A wind of particles seems to be spreading out from the neutron star’s equator like wispy smoke rings, but they are traveling at half the speed of light.

 

Courtesy of NASA/CXC/ASU/J.Hester et al.

Cassiopeia A

Just before it explodes as a supernova, a massive star is like an onion, with layers of different chemical compositions atop one another. In this color-coded Chandra image of the supernova remnant Cassiopeia A, the bluish-violet areas are the remains of the star’s innermost core, consisting largely of iron, the last element the star created before it exploded. The red is silicon from the next layer out. Green marks the spherical shock wave that precedes the great mass of material still rushing outward three centuries after the star detonated. Most of this material cannot be seen with optical telescopes. “They don’t get the big picture that X-rays show,” says NASA’s Una Hwang, who made this image. “Optical observers are looking just at the tip of the iceberg.”

Courtesy of NASA/CXC/CSFC/U. Hwang et al.