Lecture Notes on The Sun II - Lecture 26 | ASTR 105G, Study notes of Astronomy

Download Lecture Notes on The Sun II - Lecture 26 | ASTR 105G and more Study notes Astronomy in PDF only on Docsity! Lecture 26 The Sun II ASTR 105G: The Planets April 30, 2009 Announcements 1. Lab today “Review for Final” pages 195-200 2. Last observatory night tonight! 3. The review session will be held Wednesday at 4pm - bring questions! Last time ... • We talked about the basic parameters of the Sun • Why it stays in one piece in equilibrium • Nuclear fusion: proton-proton chain • The hot corona, cooler chromosphere, even cooler photosphere 1 Solar Physics 1.1 Structure of the Sun Internal Stratification of the Sun, and Figure 14.3 Refer to Figure 1 The Convection Zone • Extends about 30%, or 200 Mm into the interior • 2 million K at the base of this zone • The convection transports huge amounts of heat from the base to the photosphere • Material expands as it rises and cools • simulation of convection1 1http://www.solarviews.com/raw/misc/convect.mpg Lecture 26 April 30, 2009 2 / 5 Figure 1: The temperature profile of the Sun with depth, showing the inner regions.