The Hubble bubble?

The NASA/ESA Hubble Space Telescope continues to produce stunning images. Let’s examine a particularly pretty recent treat, revealing the aftermath of a cosmic disaster.

Image of supernova remnant

The Smoke Ring? The image evokes SF author Larry Niven's celebrated creation. (Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA). Acknowledgement: J. Hughes (Rutgers University))

Like so many beautiful astronomical sights, the delicate sphere in this delightful image is the remains of a cataclysmic event. About four centuries ago, a tiny white dwarf star about the same diameter as Earth, but with a mass equivalent to the Sun, swung in a tight orbit about some larger star. The white dwarfòÀÙs intense gravity tore material from its more massive companion. This stolen matter was mainly hydrogen, fuel for nuclear fusion. As it accumulated, white hot plasma thickly coated the dwarf star in an incandescent ocean until a crucial combination of heat and pressure was reached and suddenly the staròÀÙs surface became one huge detonating H-bomb! ˆàAstronomer call these titanic explosions Type 1a supernovae

The vast expanding blast wave ripped through the nearby interstellar medium. Called SNR B0509-67.5, this supernova remnant is located in the Large Magellanic Cloud (LMC), a small galaxy about 160 000 light years from Earth. This bubble-shaped shroud of gas is 23 light years across and is expanding at more than 18 million km/h.