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

rhertz <hertz778@gmail.com> wrote:

On Sun, 29 Sep 2024 11:42:18 +0000, Paul.B.Andersen wrote:
 

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"
>
?f/f = ??/? = z = GM/c? (1/R - 1/r) = ?(R)/c? - ?(r)/c?

>
  ??/? = GM/Rc?  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
>
>
?(R)/c? = 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
>
??/? = GM/Rc? = 7.65e-7
>
Which is less than the red shift from the Sun.
>

>
In comparison, ?(RSun)/c? = 0.000002327

>
M = 1.989E+30 kg
R = 696340e3 m
>
??/? = GM/Rc? = 2.12e-6
>
>
>

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

>
Now you know.

 
***************************************************************
QUOTE:
--------------------------------------------------------------------
The biggest star in the universe (that we know of), UY Scuti is a
variable hypergiant with a radius around 1,700 times larger than the
radius of the sun.
 
 
To put that in perspective, the volume of almost 5 billion suns could
fit inside a sphere the size of UY Scuti.
 
 
The star lies near the center of the Milky Way, roughly 9,500
light-years away from Earth. Located within the constellation Scutum, UY
Scuti is a hypergiant star. Hypergiants — larger than supergiants and
giants — are rare stars that shine very brightly. They lose much of
their mass through fast-moving stellar winds.
 
 
https://www.space.com/41290-biggest-star.html
**************************************************************
 
You didn't even try to read the OP, from where I extracted the data,
idiot.
 
This is another link:
 
Star UY Scuti is so big, you could fit 5 billion Suns inside it
 
https://www.skyatnightmagazine.com/space-science/uy-scuti
 
 
 
Here it's claimed that they don't have a clue about its mass:
 
https://en.wikipedia.org/wiki/UY_Scuti
 
 
So, rela-astrophysicists come out with any shit, as they are not
accountable for what they publish.

Reading isn't your strongest point, is it?
By Wikipedia, the best mass estimate is smaller than 10 solar masses,
with a radius probably extending beyond Mars.
This implies a negligeable gravitational red shift,
so the answer to your question is: red, red, and red,

Jan