Age
The angular expansion of the nebula can also be used to estimate its age. If it has been expanding at a constant rate of 10 milliarcseconds a year, then it would take 1000 ± 260 years to reach a diameter of 20 arcseconds. This may be an upper limit to the age, as ejected material will be slowed as it encounters material ejected from the star at earlier stages of its evolution, as well as the interstellar medium.
Read more about this topic: Cat's Eye Nebula
Famous quotes containing the word age:
“A painter like Picasso, who runs through many periods and phases, ends up by saying all those things which are on the tip of the tongue of the age to say, and finally sterilizes the originality of his contemporaries and juniors.”
—Norbert Wiener (1894–1964)
“No humane being, past the thoughtless age of boyhood, will wantonly murder any creature which holds its life by the same tenure that he does. The hare in its extremity cries like a child. I warn you, mothers, that my sympathies do not always make the usual philanthropic distinctions.”
—Henry David Thoreau (1817–1862)
“Every age has its temptations, its weaknesses, its dangers. Ours is in the line of the snobbish and the sordid.”
—Rutherford Birchard Hayes (1822–1893)