Introduction to Cosmology Ryden · Problem 7.3

Dark Matter

Physics — Astrophysics · gravitational-lensing-deflection-angle

Problem

A light ray just grazes the surface of the Earth (M=6.0×1024M = 6.0 \times 10^{24} kg, R=6.4×106R = 6.4\times10^6 m). Through what angle α\alpha is the light ray bent by gravitational lensing? (Ignore the refractive effects of the Earth's atmosphere.) Repeat your calculation for a white dwarf (M=2.0×1030M = 2.0 \times 10^{30} kg, R=1.5×107R = 1.5 \times 10^7 m) and for a neutron star (M=3.0×1030M = 3.0 \times 10^{30} kg, R=1.2×104R = 1.2 \times 10^4 m).

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