The Hubble Space Telescope has captured a turning point in the death of a sun-like star: the instant when the hydrogen and helium at the star's core are flung into interstellar space to create more heavenly bodies.
"This is probably very much like what will happen to the sun," California Institute of Technology astronomer William Latter said Thursday as the new Hubble images were released by the Space Telescope Science Institute.
However, our sun is much younger than the star snapped in the new pictures, and will not approach this phase for about 4.5 billion years, Latter said.
This brief period in the stellar death process actually lasts about 1,000 Earth years, a mere blink in cosmological time.
When a star starts to die, Latter said, the nuclear fuel at its heart runs out and a very dense, cool shell of hydrogen molecules is deposited around the star. This molecular shell cannot be seen, but Hubble's infrared camera snapped its image.
The dying star in question, known as NGC7027 and located 3,000 light-years from the sun in the direction of the constellation Cygnus the Swan, is seen in the new pictures as a glowing white ball surrounded by red wisps of the dissipating molecular shell.
The molecular shell is atomized and the resulting atoms are flung into space as the most primitive building blocks for other stars, planets, and any life that may form on them, Latter said.
"What's new about these images is that we're able to see a very thin transition between the ionized region and the formerly invisible atmosphere on the star," he said.
Also on Thursday, the telescope institute released images of two other dying stars that look like butterflies emerging from their cocoons. These two - known as the Cotton Candy nebula and the Silkworm nebula - show the moribund stars blowing off the shells of gas that had surrounded them after their nuclear cores were exhausted.
The gaseous shells give the stars their butterfly-wing shape, astronomers said.
