Announce: 

The problem given by Dr. Kuramoto in last lecture.

Q: Suppose a star having a mass and absolute luminosity same as those of our Sun in a constellation. According to astronomical observations, this star is revealed to have a periodic motion with period of 250 days and velocity amplitude of 5 m/s along the line of sight. Estimate the mass and orbital radius of a planet which presumably orbits around this star, and discuss the possibility of life on this planet and on its satellites.