ASTR 2010 Lecture Notes - Lecture 6: Nuclear Fusion, Neutrino, Solar Core
Document Summary
Review questions: how does the sun compare to other stars in the galaxy, but the constant sun in its diurnal journey reveals little of its true nature. On the cosmic scale, the sun is an average, middle-aged star and similar to countless others found in the galaxy. To us it dominates the sky as the nearest star, only one astronomical unit from the earth. The sun is an immense body containing 99% of the material in the entire solar system. Its diameter of 142. 6 million kilometers (886,000 miles) is equivalent to 109-earth diameters. More than 300 earths would be needed to form a ring around its equator. The sun is made of 70% hydrogen and 28% helium. The composition of the sun is nevertheless similar to that of other stars. The sun"s central temperature is about 15. 6 million kelvins (28 million of).
