NGC 6891 is an intense, unbalanced planetary nebula in the constellation Delphinus, theDolphin This Hubble image exposes a wealth of structure, consisting of a round external halo that is broadening quicker than the inner nebula, and a minimum of 2 ellipsoidal shells that are orientated in a different way. The image likewise exposes filaments and knots in the nebula’s interior, surrounding the main white dwarf star. From their movements, astronomers approximate that a person of the shells is 4,800 years of ages while the external halo is some 28,000 years of ages, suggesting a series of outbursts from the passing away star at various times.
Hubble studied NGC 6891 as part of efforts to assess the ranges to nebulae, and to get more information about how their structures formed and progressed. NGC 6891 is comprised of gas that’s been ionized by the main white dwarf star, which removed electrons from the nebula’s hydrogen atoms. As the stimulated electrons go back from their higher-energy state to a lower-energy state by recombining with the hydrogen nuclei, they give off energy in the kind of light, triggering the nebula’s gas to radiance.