Distinction Between Binary Stars and Other Double Stars
Visual double stars may be distinguished from binary stars by observing their relative motion. If the motion is part of an orbit, or if the stars have similar radial velocities or the difference in their proper motions is small compared to their common proper motion, the pair is probably physical. When observed over a short period of time, the components of both optical doubles and long-period visual binaries will appear to be moving in straight lines; for this reason, it can be difficult to distinguish between these two possibilities.
Read more about this topic: Double Star
Famous quotes containing the words distinction between, distinction, stars and/or double:
“There is all the difference in the world between the criminal’s avoiding the public eye and the civil disobedient’s taking the law into his own hands in open defiance. This distinction between an open violation of the law, performed in public, and a clandestine one is so glaringly obvious that it can be neglected only by prejudice or ill will.”
—Hannah Arendt (1906–1975)
“Met face to face, these Indians in their native woods looked like the sinister and slouching fellows whom you meet picking up strings and paper in the streets of a city. There is, in fact, a remarkable and unexpected resemblance between the degraded savage and the lowest classes in a great city. The one is no more a child of nature than the other. In the progress of degradation the distinction of races is soon lost.”
—Henry David Thoreau (1817–1862)
“Victorian sorrow: the stars are winking in the sky, but not for us.”
—Mason Cooley (b. 1927)
“Actually being married seemed so crowded with unspoken rules and odd secrets and unfathomable responsibilities that it had no more occurred to her to imagine being married herself than it had to imagine driving a motorcycle or having a job. She had, however, thought about being a bride, which had more to do with being the center of attention and looking inexplicably, temporarily beautiful than it did with sharing a double bed with someone with hairy legs and a drawer full of boxer shorts.”
—Anna Quindlen (b. 1952)