Lab 9: Estimating Stellar Radii Using the Concept of Heat Transfer via Radiation Objectives In this lab, the radii of stars can be measured using the Stefan-Boltzmann law. Luminosity and temperature is needed for the calculations. Luminosity is the power radiated from the star, while T is the surface temperature radiated, measured in Kelvin. Introduction Heat can be transferred by three means: conduction, convection and radiation. Conduction is the transfer of heat via atomic collision. Conduction works best in denser materials, e.g., solids rather than gases. Cooking with a frying pan is an example of heat conduction where the heat is transferred from the bottom of the pan to the top of the pan to the food. Convection is the transfer of heat via transfer of heated fluid (i.e., liquid or gas). Examples of convection include coolant flow in an auto cooling system and cooling by a ceiling fan. Radiation is the transfer of heat via electromagnetic waves (principally microwaves and infrared). The microwave oven and solar radiation are examples of radiant heat transfer. This lab focuses on heat transfer via radiation, using the Stefan-Boltzmann law to determine the radius of a star. The Stefan-Boltzmann law describes how much power