The Ring Nebula’s unique shape makes it extremely popular with astronomers, but NASA’s Hubble Space Telescope recently revealed the nebula’s true shape.
According to C. Robert O’Dell of Vanderbilt University, the Ring Nebula’s true shape is more like a jelly doughnut than a bagel, because it contains material in the middle.
O’Dell and his colleagues turned to Hubble and several ground-based telescopes to obtain the most detailed image yet of the Ring Nebula. Upon analyzing the image, they discovered a much more complex structure than previously thought. Using this image, astronomers built a more accurate 3-D model of the nebula.
O’Dell points out that Hubble’s detail allows astronomers to view a wildly different shape of the iconic nebula than what’s been viewed for decades. Found in the constellation Lyra, the nebula is approximately 2,000 light-years from Earth and measures about one light-year across. Earlier observations by several telescopes had detected the “jelly” in the Ring Nebula, but it took the Hubble’s Wide Field Camera 3 to reveal the ring’s central region in greater detail. According to Odell’s team, the ring wraps around a blue, football-shaped structure. Each side of the structure sticks out of opposite sides of the ring.
In the Hubble image above, the blue structure is the glow of helium, which glows due to radiation from the white dwarf star (the white dot in the center of the ring). The white dwarf is the stellar remnant of a sun-like star that has used up all of its hydrogen fuel and has gotten rid of its outer layers of gas to gravitationally collapse to a compact object.
Hubble also gave astronomers a more detailed look at the random knots of dense gas entrenched along the inner rim of the ring. These knots of gas formed when expanding hot gas made its way into cool gas ejected previously by the ill-fated star. The astronomers matched up the knots with the spikes of light around the main ring, which are a shadow effect. The original star was a lot more massive than our sun. After billions of years turning hydrogen into helium in its core, the star started to run out of fuel. It grew into a red giant. During this phase, the star got rid of its outer gaseous layers and started to collapse as fusion reactions began to diet out. Ultraviolet light from the dying star energized the gas, giving it its glow.
The outer rings were created when faster-moving gas collided with slower-moving material. The nebula is amplifying at more than 43,000 miles an hour, but the center is moving a lot quicker than the expansion of the main ring. Over the next 10,000 years the iconic nebula will continue to expand, becoming fainter and fainter until it becomes lost in the interstellar medium. Hubble’s stunning image of the Ring Nebula gives scientists a better idea of what will happen to the sun in another six billion years.
