Questions: Part 3. The luminosity and mass for main sequence stars are connected:
L ~ M^3.5
Question #6. (2 points) A star with a mass of 2 M⊙ has a luminosity of 11.3136 L⊙ while a star with luminosity of 3,160 L⊙ has an approximate mass of M⊙.
Transcript text: Part 3. The luminosity and mass for main sequence stars are connected:
\[
L \sim M^{3.5}
\]
Question #6. (2 points) A star with a mass of $2 \mathrm{M} \odot$ has a luminosity of 11.3136 L $\odot$ while a star with luminosity of $3,160 \mathrm{~L} \odot$ has an approximate mass of $\mathrm{M} \odot$.
Solution
Solution Steps
Step 1: Understanding the Luminosity-Mass Relationship
The given relationship between luminosity \(L\) and mass \(M\) for main sequence stars is:
\[
L \sim M^{3.5}
\]
Step 2: Solving for Mass Given Luminosity
We need to find the mass of a star given its luminosity. The relationship can be written as:
\[
L = k M^{3.5}
\]
where \(k\) is a constant. For a star with a mass of \(2 \, M_\odot\) and a luminosity of \(11.3136 \, L_\odot\), we can determine \(k\).
Step 3: Determining the Constant \(k\)
Using the given values:
\[
11.3136 = k (2)^{3.5}
\]
\[
11.3136 = k \cdot 11.3137
\]
\[
k \approx 1
\]
Step 4: Using the Constant to Find the Mass
Now, we use the constant \(k \approx 1\) to find the mass of a star with a luminosity of \(3,160 \, L_\odot\):
\[
3,160 = 1 \cdot M^{3.5}
\]
\[
M^{3.5} = 3,160
\]
\[
M = (3,160)^{1/3.5}
\]