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:
“If he does really think that there is no distinction between virtue and vice, why, Sir, when he leaves our houses let us count our spoons.”
—Samuel Johnson (1709–1784)
“We mustn’t be stiff and stand-off, you know. We must be thoroughly democratic, and patronize everybody without distinction of class.”
—George Bernard Shaw (1856–1950)
“Throw the children into the river; civilization has given us too
many.
It is better to die than to grow up and find that you are colored.
Pluck the stars out of the heavens. The stars mark our destiny. The
stars marked my destiny.
I am tired of civilization.”
—Fenton Johnson (1886–1958)
“O, my offense is rank, it smells to heaven;
It hath the primal eldest curse upon ‘t,
A brother’s murder. Pray can I not,
Though inclination be as sharp as will;
My stronger guilt defeats my strong intent,
And like a man to double business bound
I stand in pause where I shall first begin,
And both neglect. What if this cursed hand
Were thicker than itself with brother’s blood,
Is there not rain enough in the sweet heavens
To wash it white as snow?”
—William Shakespeare (1564–1616)