This peaceful cloud of gas belies a great deal of activity deep within the nebula.NGC 6891 glows brilliantly in a new image from the Hubble Space Telescope, as the observatory helps researchers in finding out more about how these gas clouds formed and evolved.Astronomers call NGC 6891 a “planetary nebula,” a term emerging from an old misidentification with worlds back when telescope innovation remained in its infancy. Today we understand that such nebulas form after supernova surges that see big stars shed gas. A white dwarf residue of the star stays behind, slowly cooling.Related: The finest Hubble Space Telescope images of all time!The planetary nebula NGC 6891 glows in this Hubble Space Telescope image. (Image credit: NASA, ESA, A. Hajian (University of Waterloo), H. Bond (Pennsylvania State University), and B. Balick (University of Washington); Processing: Gladys Kober (NASA/Catholic University of America)) The Hubble Space Telescopes high-definition imagery exposed filaments and knots wrapped around the white dwarf ingrained deep within the cloud. The information likewise reveals that the external halo of gas is broadening faster than the innermost part of the nebula, and the observations even capture shells of gas that are oriented in various directions.” From their motions, astronomers approximate that a person of the shells is 4,800 years of ages while the outer halo is some 28,000 years old, showing a series of outbursts from the dying star at different times,” NASA authorities wrote in a statement.The radiant from NGC 6891 happens as the white dwarf stars ionizes, or strips away electrons, from the surrounding hydrogen gas. ” As the energized electrons revert from their higher-energy state to a lower-energy state by recombining with the hydrogen nuclei, they discharge energy in the kind of light, causing the nebulas gas to radiance,” NASA said.Hubble is presently in healing from a synchronization glitch that happened on Oct. 23 and its instruments are gradually being revived online. Hubble was last serviced face to face in 2009 and with the retirement of the space shuttle bus, is no longer accessible to astronauts. That said, the 31-year-old telescope has plenty of archival information to process.Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom or on Facebook..
