kepler's supernova remnant

Kepler’s Supernova Remnant

Kepler’s Supernova Remnant was first observed in 1604 by many astronomers, including Johannes Kepler. It is a remnant from a Type 1a supernova, where a white dwarf star acretes mass either from a nearby star or by colliding with another white dwarf. With enough mass, the star goes unstable and explodes, leaving behind a debris field.

Kepler’s Remnant is unusual because it is much less symmetrical than most Type 1a remnants. The bright arc of X-ray emission indicates that the expanding debris is colliding with other material. One idea is that the star was moving through space and losing material , creating a bow shock, before exploding. Another is that the debris is expanding into a cloud of increasing density. The first hypothesis would set the remnant more than 23,000 light years away, while the second places it between 16,000 and 20,000 light years from Earth.

This image shows the remnant in colors relating to the energy of the observed X-rays. The X-ray spectrum present indicates a high amount of iron, evidence for a more energetic explosion. Additionally, a small area would have to have been cleared from around the star before the explosion, possibly caused by a dense outflow from the star.

Kepler clue to supernova puzzle

Two white dwarfs favoured as precursors of type Ia supernovae.

They are cosmic detonations that briefly outshine the light of entire galaxies. And they were a crucial tool in the discovery of dark energy, the force that is accelerating the expansion of the Universe. Yet the process that gives rise to type Ia supernovae has remained mysterious.

Now, light from two of these stellar explosions has been captured in finer temporal detail than ever before, and the data are adding weight to an emerging view: that the explosions result from the merger of two white dwarfs, the burnt-out, Earth-sized remnants of Sun-like stars. The finding erodes a long-standing view that type Ia supernovae arise from a single white dwarf accruing material from an ordinary companion star, either a Sun-like star or an elderly, bloated red giant.

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