2019年IOAA理论第2题-太阳系天体的引力透镜

英文题目

2. Deflection of radio photons in the gravitational field of solar system bodies (10 p) A. Eddington and F. Dyson from Principe, and C. Davidson and A. Crommelin from Sobral, Brazil measured the deflection of light coming from stars apparently very close to the Sun during the total solar eclipse in 1919. The deflection was found to agree with the theoretically predicted value of 1.75". A light ray (or photon) which passes the Sun at a distance 𝑑 is deflected by an angle

$$Δθ=\frac{4GM}{dc^2}$$

The present-day accuracy of the VLBI (Very Long Baseline Interferometry) technique in the radio wavelength range is 0.1 mas (milliarcsecond). Is it possible to detect a deflection of radio photons from a quasar by (a) Jupiter, (b) the Moon? Estimate the angle of deflection in both cases and mark "YES" or "NO" on the answer sheet.