Re: Gravitational red-shifting in the biggest star. What are the real colors?

Den 28.09.2024 04:34, skrev rhertz:

This link illustrates a bit:
 https://en.wikipedia.org/wiki/Gravitational_redshift
 Using the most common formula from that link: "To first approximation,
gravitational redshift is proportional to the difference in
gravitational potential divided by the speed of light squared"
 Δf/f = Δλ/λ = z = GM/c² (1/R - 1/r) = Φ(R)/c² - Φ(r)/c²

  Δλ/λ = GM/Rc²  observed at infinity  (r -> ∞)
https://www.space.com/41290-biggest-star.html

 G = 6.6743E−11 m^3 kg^−1 s^−2
M = 5E+09 x 1.989E+30 Kg = 9.945E+39 Kg
R = 1,700 x 634,000 Km = 1,077,800,000,000 m
  Φ(R)/c² = 6,842,736.59

 From whence did you get the idiotic idea that the mass
of UY Scuti was 5 billion solar masses? :-D
M = 30 solar masses =  5.967e31 kg
R = 696340e3⋅1700 m = 57868e6 m
c = 299792458 m/s
Δλ/λ = GM/Rc² = 7.65e-7
Which is less than the red shift from the Sun.

 In comparison, Φ(RSun)/c² = 0.000002327

M = 1.989E+30 kg
R = 696340e3 m
Δλ/λ = GM/Rc² = 2.12e-6

 WHAT IS WRONG WITH MY CALCULATIONS, BASED ON THE WIKI LINK?

Now you know.
--
Paul
https://paulba.no/