Tycho’s Supernova

In 1572, Danish astronomer Tycho Brahe was among those who reported a new bright object in the constellation Cassiopeia. We now know that Tycho’s new star was not new at all. It was a supernova, a stellar explosion so bright that it can outshine the light from rest of the galaxy. This particular supernova was a Type Ia, which occurs when a white dwarf star pulls material from, or merges with, a nearby companion star until a violent explosion is triggered. The white dwarf star is obliterated, sending its debris hurtling into space.

This false color image of the remnant of Tycho’s supernova combines from the Chandra X-ray Observatory with optical data from the Digitized Sky Survey. It uses date from two narrow ranges of X-ray energies to isolate material (silicon, colored red) moving away from Earth, and moving towards us (also silicon, colored blue). The other colors in the image (yellow, green, blue-green, orange and purple) show a broad range of different energies and elements, and a mixture of directions of motion.

Image Credit: X-ray—NASA / CXC / RIKEN & GSFC / T. Sato et al; Optical: DSS

A Supernova Remnant

tycho_1Over four centuries after Tycho Brahe first observed the supernova that bears his name, the supernova remnant it created is still a bright source of X-rays. The supersonic expansion of the exploded star produced opposing shock waves, one moving outward into the surrounding interstellar gas and another moving back into the expanding stellar debris. This Chandra image of Tycho reveals the dynamics of the explosion’s interfering shock waves in detail. The outer shock has produced a rapidly moving shell of extremely high-energy electrons (blue), and the reverse shock has heated the expanding debris to millions of degrees (red and green). There is evidence from the Chandra data that the interference between these shock waves may be responsible for some of the ultra-energetic particles that pervade the Galaxy and constantly bombard the Earth as cosmic rays.

Image Credit: NASA