how many times brighter is A-4 star then A-6?

[KayleaC]

astronomy help!!hypothetical stars in a homework question.

[lindajune9404]

Star A-4 and A-6...there are no stars with these labels or designations in the sky.Are these specific stars (it would help if you gave us their actual names or constellation designations), or are these hypothetical stars in a homework question and you have left out the details.

[injanier3598]

I'm guessing if this is your homework you probably have access to more pertinent information than most of us. Lacking that, you'll have to use actual star data and try a curve fit. From this table http://www.cosmobrain.com/cosmobrain/res/brightstar.html you can findA7V - 2.2 (Altair)A3V - 1.73 (Fomalhaut)A1V - 0.02 (δ Vel)You didn't specify a luminosity class, so I just used more or less normal dwarfs. Since the luminosity of a given classification can vary considerably with metallicity, you'll want to either carefully select for that or use a large enough sample to get a good average.

[1635]

If you mean how much brighter is a star with apparent magnitude -4 than a star with apparent magnitude -6 (apparent magnitude just means how bright it appears to us on Earth), then the -4 star isn't brighter, it is actually 6.25 times fainter.This is because the magnitude system is a logarithmic one, where a star with a magnitude 1 higher is actually 2.5 times brighter.