ASTR 1346 1st Edition Lecture 5 Outline of Last Lecture I Convection II Conduction III Radiation IV Helioseismology A GONG B SOHO C SDO Outline of Current Lecture I Nuclear Fusion A E mc 2 B Neutrinos II Composition of Solar Atmosphere A Granules B Sunspots C Sunspot Maximum and Minimum D Solar Magnetism E Sunspot Cycle Current Lecture l Nuclear fusion is when one nucleus combines with another nucleus and creates a third nucleus combined with energy The final step in nuclear fusion is when 4 hydrogen nuclei combine and fuse to create 1 helium nucleus plus some energy in the form of gamma rays and 2 neutrinos These gamma rays slowly degrade in energy as they pass through the solar interior Eventually they leave the solar surface in the form of visible light A E mc 2 is energy mass X speed of light squared This is the law of conservation of mass and energy created by Albert Einstein and explains that matter and energy can t be created nor destroyed but they can be changed in form B Neutrinos carry no electrical charge are very low in mass interact with hardly anything so they escape from the Sun into space and they pass underneath Earth These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute ll Our Sun is made of plasma which is a state between a solid and a gas with extremely high temperature 67 elements have been identified in the Sun 91 is Hydrogen and the other 9 is Helium A Granules are small cellular features of rising hot gas that cover the entire photosphere Their life time is 5 10 minutes and they re about the size of Texas B Sunspots typically measure 10 000km across which is about the size of Earth The darker part of a sunspot is called the umbra and is around 4 500K The lighter part is the penumbra and is around 5 500K Sunspots are slightly cooler than their surroundings which is why they re darker than the rest of the Sun All sunspots occur near the equator C The Sun may have hundreds of sunspots which is sunspot maximum and is 15 20 degrees away from the equator or none at all which is sunspot minimum and is 10 degrees away from the equator The Maunder Minimum was a period of time 16451715 when there were no sunspots and this made the Earth very cold D Solar magnetism is when the magnetic field is 1 000 to 5 000 times stronger than in surrounding areas creating a sunspot E A sunspot cycle is the number of spots that changes roughly over 11 years