Distances, Magnitudes and Spectral Classes Equations

m = -2.5 log I + constant

d = R / tan θ_p   (d = Distance (m))

θ_p = (t / 3600)°

θ = 2θ_p = W / d   (d = Distance (m))

m_b - m_a = 2.5 log (L_a / L_b)

m - M = 5 log (d / 10)      (d = Distance (parsecs))

R (Radius of Earth Orbit and 1 Astronomical Unit (AU)) = 1.5x10¹¹ m

W (Width of Earth Orbit) = 3x10¹¹ m

1 pc = 3.09x10¹⁶ m

1 Mpc = 3.09x10²²m

m, m_a, m_b (Apparent Magnitude)

I (Intensity) = W m^-2

θ_p (Angle of Parallax) = degrees

t (Time of Parallax) = s

L_a, L_b (Luminosity) = W

M (Absolute Magnitude)

©2011 Grant Dwyer