A penetrating look at Kepler's supernova

The Chandra Space Telescope helped solve a 400-year-old mystery, and in a series of X-rays it revealed that it originated from the explosion of a white dwarf that accreted material from its companion star, a type of supernova known as la, but also a rare type within this group 

 The Chanarda X-ray space telescope has produced this stunning image of one of the youngest supernova remnants in our galaxy. The supernova shone in the sky over 400 years ago, before the invention of the telescope. But it was so bright that a telescope was not needed to observe it - it reached the brightness of the planet Jupiter at its peak. And one of the greatest astronomers in history, Johannes Kepler, was there to watch it.

Now, 400 years later, the Chandra Space Telescope has turned its attention to Kepler's supernova remnant and this is what it saw. The image was made by combining Chandra observations over nine days and assembled into a single X-photograph.

Before these observations, the bone remained a mystery. It seems to have large amounts of iron and no neutron star was found in its core - which would indicate that it was a type la supernova, in which a white dwarf exploded after swallowing material from a companion star. However, visible light photographs showed that the object spread into a compressed cloud of nitrogen-rich material. This may indicate that this is a type II supernova where one massive star sings off a layer of material before exploding.

Chandra's new observations helped solve the mystery. The astronomers calculated the relative amount of oxygen and iron in the remnant cloud, and determined that these amounts indicate the existence of the type la supernova. It is possible that it is nevertheless a rare configuration of a type la supernova in which the star explodes a hundred million years after starting to swallow material from the companion star and not billions of years after they become white dwarfs and therefore begin the process of absorbing material.