How many times brighter or fainter would a star appear if it were moved to: a. twice its present distance? b. ten times its present distance? c. half its present distance?

17 Which of the following statements about parallax is not true? A You can demonstrate parallax simply by holding up a finger and looking at it alternately from your left and right eyes. B C D The existence of stellar parallax is direct proof that Earth orbits the Sun. Measurement of stellar parallax allows us to determine distances to nearby stars. The technique of stellar parallax was used by Hubble to determine that the Andromeda Galaxy (M 31) is about 2 million light-years away. Ancient astronomers were unable to measure parallax and used the absence of observed parallax as an argument in favor of an Earth-centered universe.

I attempted to answer this question and I'm not sure what I am doing wrong. My formula says A.S. = 206265 (separation/distance from observer) I know to convert to the same units, so I ended up with 80 Million Km being 8 x 10 ^ -6 LY Could you please explain each step especially for the part that I got wrong for both A and B?

1Which of the following best describes a frame of reference?   an experiment that proved that Earth did not have an aether wind   the theory that describes the behavior and characteristics of objects moving at relativistic speeds   the effect of the slowing of time as an object moves with high speeds   a point in which someone relates the behavior of an object from one perspective 2If an electron moves from n = 5 to n = 1, what wavelength of light is emitted? (h = 6.626 x 10-34, 1 eV = 1.6 x 10-19 J)   4008 nm   434 nm   95 nm   1281 nm   3Which of the following best describes a frame of reference?   an experiment that proved that Earth did not have an aether wind   the theory that describes the behavior and characteristics of objects moving at relativistic speeds   the effect of the slowing of time as an object moves with high speeds   a point in which someone relates the behavior of an object from…