所有的恒星都会发出光和热.All the stars send out light and heat.这样的天体本身也可能发出光, 但是它的重力最后还是会把光吸引回去.Light itself could leave from such an object, but gravity would eventually pull it back again.脉冲星是一种能够发出光脉冲的天体.A pulsar is a celestial o...