Answer to Question #87196 in Astronomy | Astrophysics for Amit

Question

The absolute visual magnitude of a star is 6.5 and for its temperature, the bolometric correction is − 0.3. Calculate the absolute bolometric magnitude and the luminosity of the star.

Answer 1

The expression for the absolute magnitudes of a star are written as:

$$M_{bol}=M_{v}+B.S. (1)$$

where M_bol is the absolute bolometric magnitude of a star, M_v is the absolute visual magnitude of a star, B.C. is bolometric correction

Using (1) we got: M_bol = 6.5-0.3=6.2

The formula relating absolute bolometric magnitude with luminosity is as follows:

$$L_{star}= L_ʘ\times 10^{-0.4M_{bol}} (2)$$

where L_ʘ is the zero-point luminosity (the luminosity of a star with M_bol=0)

We find:

L_star=0.003 L_ʘ

Answer:

M_bol = 6.2

L_star=0.003 L_ʘ