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 nothing more likely to drive a man mad, than the being unable to get rid of the idea of the distinction between right and wrong, and an obstinate, constitutional preference of the true to the agreeable.”
—William Hazlitt (1778–1830)
“The word “jealousy” is often used as if it were synonymous with envy; but I think the distinction worth preserving. Jealousy is predominantly concerned with the fear of loss of something one possesses, envy with the wish to own something another possesses. Othello suffers from the fear that he has lost Desdemona’s love. Iago suffers from envy of the position held by Cassio, to which he feels entitled.”
—Anthony Storr (b. 1920)
“The stars have grooved our eyes with old persuasions
Of love and hatred, birth,—surcease of nations . . .”
—Hart Crane (1899–1932)
“... the next war will be a war in which people not armies will suffer, and our boasted, hard-earned civilization will do us no good. Cannot the women rise to this great opportunity and work now, and not have the double horror, if another war comes, of losing their loved ones, and knowing that they lifted no finger when they might have worked hard?”
—Eleanor Roosevelt (1884–1962)