A star has an Apparent Visual Magnitude of +8 and a stellar parallax of 0.0251 second of arc. What is the approximate value of the Absolute Visual Magnitude of this star?
A. +2.51
B. +3
C. +5
D. +7
2007-11-05 10:57:48 · 3 answers · asked by tdoby3 2 in Science & Mathematics ➔ Astronomy & Space
Divide 1 sec by 0.0251 sec. =39.84, say 40. So it is 40 parsecs away. Absolute mag is taken at 10 parsecs, 1/4 of that distance. 1/4 the distance would be 16 times the apparent brightness. One magnitude is the log 5 of 100, or a factor of 2.51. Three magnitudes is a factor of 16: (2.51)^3. Convenient. So 8-3 = +5.
I recognized the 2.51 as the factor per magnitude and wondered if there was a shortcut intended. But my math isn't that good.
I really had to think about this for awhile because it's been a long timesince I did this stuff. So, do I get the job?
Edit: Hey! Knock-knock...hellooooo. Hey! Knock-knock...hello? Anybody home? I had to work at this thing. An acknowledgement would be nice.
2007-11-05 11:30:46 · answer #1 · answered by Brant 7 · 2⤊ 0⤋
a million. The solar, Moon, stars, and different gadgets can been seen by using all of us on a clean night, so astronomy unites all persons. 2. A elementary aquaintance with astronomical suggestions could provide help to tell time and make sure guidelines like north and south, and the seasons devoid of an iPhone, or maybe without a compass or a watch! 3. it extremely is exciting and inspirational to think of real worlds as super as and extra beneficial than our very own as quickly as we seem up at staggering planets like Jupiter, Mars and Saturn !
2016-09-28 10:06:42 · answer #2 · answered by ? 4 · 0⤊ 0⤋
You really ought to do your own homework.
2007-11-05 11:52:10 · answer #3 · answered by Irv S 7 · 1⤊ 0⤋