2) Vega is a star that is about 25.05 ly away from Earth. The star has an apparent magnitude (m) of 0.0305. Calculate Vega's absolute magnitude.
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Verified Answer :

msm555

Answer:

0.61

Explanation:

To calculate Vega's absolute magnitude \(\bold{( M )}\), we use the distance modulus formula, which relates apparent magnitude \(\bold{( m )}\), absolute magnitude \(\bold{( M )}\), and distance in parsecs \(\bold{( d )}\):

\(\large\boxed{\boxed{\sf m - M = 5 \log_{10}(d) - 5 }}\)

First, we need to convert the distance from light years to parsecs.

Given that 1 parsec (pc) is approximately 3.262 light years (ly), we calculate:

\(\sf d = \dfrac{25.05 \, \textsf{ly}}{3.262 \, \textsf{ly/pc}} \approx 7.68 \, \textsf{pc}\)

Nextsf, we use the distance modulus formula:

\(\sf m - M = 5 \log_{10}(d) - 5\)

Substitute \(\bold{ m = 0.0305 }\) and \(\bold{ d = 7.68 }\):

\(\sf 0.0305 - M = 5 \log_{10}(7.68) - 5\)

\(\sf 0.0305 - M = 5 \times 0.88536 - 5\)

\(\sf 0.0305 - M = 4.4268 - 5\)

\(\sf 0.0305 - M = -0.5732\)

Solving for \(\bold{ M }\):

\(\sf M = 0.0305 + 0.5732\)

\(\sf M = 0.6037\)

\(\sf M = 0.61 \textsf{(in 2 d.p.)}\)

Thus, the absolute magnitude of Vega is approximately:

\(\sf M \approx 0.61\)