Question

The star Rigel, otherwise known as Rājanya, has a mass of $42\times {10}^{30}\text{kg}$. Express the mass in the unit of solar mass (${\text{M}}_{\text{Sun}}$).

• A. $36{\text{M}}_{\text{Sun}}$
• B. $18{\text{M}}_{\text{Sun}}$
• C. $21{\text{M}}_{\text{Sun}}$
• D. $42{\text{M}}_{\text{Sun}}$

Answer 1

The correct option is C $21{\text{M}}_{\text{Sun}}$

Given:

Mass of the star Rigel, ${\text{M}}_{\text{R}}$
$=42\times {10}^{30}\text{kg}$

${\text{M}}_{\text{Sun}}$ $=2\times {10}^{30}\text{kg}$

${\text{M}}_{\text{R}}=\frac{42\times {10}^{30}}{2\times {10}^{30}}=21{\text{M}}_{\text{Sun}}$