New images from NASA’s Hubble Space Telescope revealed that the famous Ring Nebula is "not as simple" as scientists previously believed.
“With Hubble’s detail, we see a completely different shape than what’s been thought about historically for this classic nebula,” Robert O’Dell, who led the research team, said in a press release, explaining that, instead of a bagel, the space object is in fact “like a jelly doughnut, because it’s filled with material in the middle.”
The discovery comes from previous observations of only the gaseous material in the ring’s central region compared to the new view by Hubble’s sharp-eyed Wide Field Camera 3 that suggests the ring in fact wraps around a blue, football-shaped structure with each end of the structure protruding out of opposite sides of the ring.
The image includes a stretch of blue, signifying the glow of helium. Furthermore, radiation from the white dwarf star – seen as a white speck in the center of the structure – is exciting the helium to glow.
Historically, the white dwarf star was once a busy, lively place; however, some 4,000 years ago it ran out of hydrogen fuel, which caused it to balloon and become a red giant. During this phase, the star shed its outer gaseous layers into space and began to collapse as fusion reactions died out. As it did so, a gush of ultraviolet light from the star energized the gas, causing it to become luminescent.
O’Dell and his team were also able to find in their new image of the nebula irregular knots of dense gas similar to those found in other planetary nebulae, which are embedded along the inner rim of the ring, forming what appear to be spokes in a bicycle wheel.
Created when expanding hot gas pushed into cool gas ejected previously by the defeated star, they are more resistant to erosion by the wave of ultraviolet light unleashed by the star.
Fortunately for O’Dell and his team, the Hubble images allowed them to match up the knots with the spikes of light around the bright, main ring, which are a shadow effect.
At this point, the Ring Nebula is expanding at a rate of more than 43,000 miles an hour, though the center is moving faster than the expansion of the main ring, according to measurements the team came up with by comparing the most recent photo to those taken in 1998.
Ultimately, by studying the Ring Nebula, scientists are taking a peek into the future of the Sun itself some 6 billion years down the road; however, because the Sun is less massive than the star from which the Ring Nebula is derived, its ending will not be, according to scientists, quite as “opulent.”