if a star has a parrallax of 0.026 second of arc and an apparent magnitude of 7, how far away is it and what is its absolute magnitude
if a star has a parrallax of 0.026 second of arc and an apparent magnitude of 7, how far away is it and what is its absolute magnitude
If I remember my High school astronomy, you can calculate the distance of a nearby star if you know its parallax. Therefore:
D=1/p=1/.026 =38.46 parsecs.
38.46 x 3.26 =125.38 Light years-the distance to the star.
Not so sure about absolute magnitude, but I will give it a go!!.
Absolute magnitude is the brightness of a star at a standard distance of 10 parsecs. Since the distance to this star is 38.46 parsecs, then 38.46/10=3.846 times brighter. But since 1 magnitude represents a ratio of 2.512, then 3.846/2.512=1.5311. If we set the absolute magnitude to x, then we have: x^1.5311=7, and x=7^(1/1.5311)=3.564-The star absolute magnitude.
And that is the best I can do!!. Good luck.
