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Results tagged with astrophysics
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user 44840
The application of physical theory to celestial systems such as stars, planets, galaxies, supernovae, and black holes. Astrophysics proper is concerned with explaining phenomena more so than making observations, the latter falling under the purview of astronomy.
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Quick question on derivation of mass of star
How do I show that for a binary star system, if one star has mass $M_s$, speed $V_s$, period $P$, the mass of the other star is given by:
$$M_P^3 \approx \frac{V_s^3}{2\pi G} PM_s^2$$
I showed it us …
- 943
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Quick question on astronomical units
$$ 3.71 + 10\log\left[\frac{1}{2T^2}\left(\frac{\theta}{p''}\right)^3\right] + 5 \log(p'') = 0 $$
Using T = 171 yr, $\theta = 3.75$ as before, I realized I made an absolute amateur mistake! I used lo …
- 943
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Redshift 1+z - CMB Temperature lower?
I know that $\frac{\lambda_2}{\lambda_1} = 1 + z$
Suppose a galaxy had redshfit $z=3$. Does this mean that the wavelength becomes $4\lambda$?
Then by wien's law where $\lambda \propto \frac{1}{T}$, …
- 943
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Quick question on parallax and parsec
I know that 1 parsec (pc) is the distance of star at which 1 AU subtends 1 arcsecond.
so $1 pc = \frac{1 AU}{1"}$
Now, if two stars in a binary with a separation of 3" and have a trigonometric paral …
- 943
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Quick question on astronomical units
I'm trying to solve for $\frac{M*}{M_0}$ and $p''$ using these two equations:
Here is the lecturer's working, I worked it out several times and I got a different answer!
Surely when you use Kepler …
- 943