Image of the Day: The Calabash Nebula

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Feb 3, 2017, 6:13 PM EST (Updated)

Captured by the NASA/ESA Hubble Space Telescope, the Calabash Nebula (aka OH 231.8+04.2) in astral cluster Messier 46 may appear like a glowing alien space gourd, but this sci-fi-looking celestial phenomenon is actually a low-mass star — not unlike the sun — in its death throes.

Stars evolve from red giants into protoplanetary nebulae when they decompose into clouds of dust and gases that stream out into space at over 600 miles per hour. What you are actually seeing is the light emanating from ionized hydrogen and nitrogen atoms released in the star's violent end. Incandescent blues, yellows and oranges visible to the human eye in this image are the result of Hubble filtering out everything except those elements.

The nebula's unusual shape came to light as astronomers identified the hottest areas, which reach scorching temperatures as expanding gases zoom at warp speed and collide with other objects in the star cluster. Intense collision shock creates shock fronts (which astronomers had previously predicted but were just recently able to prove the existence of) that heat these gases to unfathomable temperatures. It is these shock-heated gases that form Calabash's unusual two-headed shape. Somewhere in the middle resides a rapidly decaying star, shrouded by a haze of dust.

Animation showing the Calabash nebula at different angles.

Instagram-worthy photo ops of a star's last breaths are actually a rare opportunity for astronomers. What was imaged by Hubble from 5,000 light years away in the Puppis constellation is believed to have happened 800 years ago (a fleeting moment in space). Also known as the Rotten Egg Nebula for its high sulfur content, Calabash will continue its savage transformation from a protoplanetary nebula into a full-fledged planetary nebula over the next 1,000 years as it emits enough ultraviolet light to light up its surrounding clouds of star stuff.

Astronomers are optimistic about Calabash being a window to understanding how fiery orbs collapse into aspherical, asymmetrical galaxies.

(via SciTech Daily)