May 23, 2013
Hubble Provides Most Detailed Image Of Ring Nebula To Date
Lee Rannals for redOrbit.com — Your Universe Online
The Ring Nebula, or Messier 57, is an archetypal planetary nebula relatively close to Earth at 2,000 light-years away. NASA said Messier 57 is the glowing remains of a Sun-like star.
The fairly bright nebula was first discovered back in the late 18th century by astronomer Antoine Darquier de Pellepoix. Charles Messier also discovered the same nebula later the same month after both astronomers were following the path of a comet through the constellation of Lyra.
Astronomers combined ground-based data with new observations using the Hubble Space Telescope to have a detailed look at the nebula and hunt for clues about its structure, evolution, physical conditions and motion. They wrote about their study of the latest Messier 57 observation in The Astronomical Journal.
From Earth's perspective, the nebula looks elliptical, but the new observations shows the nebula's shape is more complicated than previously thought. The blue gas in the nebula's center is actually a football-shaped structure that pieces the red doughnut-shaped material. The image also shows the detailed structure of the dark, irregular knots of dense gas embedded along the inner rim of the ring. These knots look like spokes in a bicycle.
"We are gazing almost directly down one of the poles of this structure, with a brightly colored barrel of material stretching away from us," the European Space Agency (ESA) wrote about the cosmic object in a statement. "Although the centre of this doughnut may look empty, it is actually full of lower density material that stretches both towards and away from us, creating a shape similar to a rugby ball slotted into the doughnut´s central gap."
The brightest part of the nebula is composed of gas thrown off by a dying star at the center of the nebula. This star is on its way to becoming a white dwarf and is very small and dense. It is the final evolutionary stage for a star like our Sun. Once a star consumes all of its hydrogen, the nuclear fuel that makes it shine expands to make the star a red giant. After this stage, the star expels its outer layers, exposing its hot core. Ultraviolet radiation from the core illuminates the material to make it glow.
Hubble celebrated its 23rd anniversary in orbit back in April, but its still actively giving astronomers the best view of the universe it can. In 2018 the veteran telescope's successor, the James Webb Space Telescope, will make its way towards space. The James Webb telescope is set to be everything the Hubble is and more.