- #1
shanepitts
- 84
- 1
Homework Statement
Homework Equations
m1-m2[/SB]=2.5log(ι2/ι1)
m-M=2.5log (d/10)2
3. The Attempt at a Solution
Not sure if my approach and answers are correct
Please help
First question: In your very first line with an equation, you changed the factor of 2.5 to a factor of 5 in front of the log. Why did you do this? This seems to be a mistake.shanepitts said:Homework Statement
View attachment 83971 [/B]Homework Equations
m1-m2[/SB]=2.5log(ι2/ι1)
m-M=2.5log (d/10)2
3. The Attempt at a Solution
View attachment 83972
Not sure if my approach and answers are correct
Please help
nrqed said:First question: In your very first line with an equation, you changed the factor of 2.5 to a factor of 5 in front of the log. Why did you do this? This seems to be a mistake.
AH yes, Ok.shanepitts said:I forgot the exponential: m-M=2.5log(d/10)2
nrqed said:AH yes, Ok.
EDIT: you seem to have made a sign mistake. In the exponential for the calculation of the luminosity, you should have
M_1 - M_2 = M_1 - ( m +1.99) = 5 -m - 1.99Then your work looks good. You just need to plug in the value of m=2. The absolute magnitude of the star is smaller than the Sun's absolute magnitude (3.99 versus 5) so the star has a larger luminosity than the Sun's and your final expression agrees with this. All the steps look good.
You are welcome. And no problem about the typo, I make typos all the time :-)shanepitts said:Thanks a bunch and sorry for the typo
Absolute magnitude is a measure of the intrinsic brightness of a celestial object, independent of its distance from Earth.
Apparent magnitude is a measure of how bright an object appears to be from Earth, while absolute magnitude is a measure of how bright an object would appear if it were placed at a standard distance of 10 parsecs away from Earth.
The formula for calculating absolute magnitude is: M = m - 5(log(d) - 1), where M is the absolute magnitude, m is the apparent magnitude, and d is the distance to the object in parsecs.
Absolute magnitude allows astronomers to compare the intrinsic brightness of celestial objects, which can provide insight into their physical properties and evolutionary stage.
The absolute magnitude of a star is determined by measuring its apparent magnitude and using the distance to the star, which can be calculated using parallax or other distance indicators.