Algerbra in Astrophysics

log(3.14) · May 30, 2009

I am realy quite terrible at rearranging equations, I wonder if anyone could help?

How can I rearrange : m-M=5log10(d/10) to give d=?

Thanks for any imput.

Cyosis · May 30, 2009

First divide by 5, [itex](m-M)/5=\log_{10}(d/10)[/itex]. To get get rid of the log_10 you take 10^ on both sides.

[tex]
10^{\frac{m-M}{5}}=\frac{d}{10}
[/tex]

Now multiply by 10.

log(3.14) · May 30, 2009

Cheers! This helps alot!

peeyush_ali · Jun 9, 2009

what is this simple calculation has to do with "Astrophysics" ...???

protonchain · Jun 9, 2009

peeyush_ali said: ↑

what is this simple calculation has to do with "Astrophysics" ...???

This is the calculation for magnitudes. It's the bane of all new undergraduate astrophysics students :tongue:

Wallace · Jun 9, 2009

Stupid backwards magnitudes! I've seen even seasoned astronomers get in a verbal tangle using the wrong adjective to describe some magnitude (i.e. 'as high as' instead of 'as low as' or vice versa). No wonder beginners have trouble...

Chronos · Jun 9, 2009

Magnitude is a pretty obscure and confusing measure of brightness. Think 2 to the fifth power.