Question -
Answer -
Mass of our galaxy Milky Way, M =2.5 × 1011 solar mass
Solar mass = Mass of Sun = 2.0 × 1036 kg
Mass of our galaxy, M = 2.5× 1011 × 2 × 1036 = 5 ×1041 kg
Diameter of Milky Way, d =105 ly
Radius of Milky Way, r = 5× 104 ly
1 ly = 9.46 × 1015 m
∴r = 5 × 104 × 9.46 × 1015
= 4.73 ×1020 m
Since a star revolvesaround the galactic centre of the Milky Way, its time period is given by therelation:
