The butterfly shape is created by the stellar ballet of the two sun-like stars at the end of their lives.
The primary star of this binary system is now a red giant, between 1.0 and 1.4 times the mass of the sun. It’s blowing away its outer gaseous envelope to expose its stellar core and will eventually contract into a white dwarf.
The other star is already a white dwarf – a slowly cooling stellar corpse – between 0.6 and 1.0 times the mass of the sun.
The white dwarf is orbiting very close to the primary star and may even have been engulfed by the other’s expanding stellar atmosphere with the resulting interaction creating the nebula.
The pair orbit each other every 100 years, and astronomers think the gravity of one star is pulling ejected material from its binary companion and twisting it into two thin iridescent lobes which are stretching far out into space.
The lobes are still growing, and by measuring their rate of expansion, scientists have calculated that the nebula was created about 1200 years ago.
A planetary nebula is effectively a huge expanding shell of gas.
These growing shells are heated up, and the kaleidoscope of colors are caused by the different chemicals being ionized.
Within the lobes of Twin Jet planetary nebula PN M2-9 are two faint blue patches streaming horizontally outwards like veins, barely visible in the nebula’s rainbow colors.
These blue patches are actually violent twin jets moving at over a million kilometers per hour out from the rapidly rotating star system.
Over time, images of these jets show that they’re slowly changing their orientation, moving across the lobes, as they’re pulled by the wayward gravity of the binary system.
This rotation not only creates the lobes and jets, it also allows the white dwarf to strip gas from its larger companion, which then forms a large disc of material around the pair.
Read more at Discovery News
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