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• What we see when we look at the Sun (with appropriate filters) NEVER LOOK DIRECTLY AT THE SUN
• Photosphere is a blackbody
• Recall: blackbodies aren't really black, they just don't reflect light
• Blackbodies emit light
• The hotter a blackbody, the higher the energy of the light it emits (shorter wavelength)
• hotter blackbodies emit more light
• Average temperature of photosphere is 5800 K
• Sun looks darker toward the edges (limb darkening)
• Caused by temperature drop with altitude in photosphere
• Association: Earth's lowest atmospheric layer (troposphere) also gets colder with altitude
• Close-up view of photosphere shows granules
• Each granule is ~1000 km across
• Granules caused by convection (lava lamp effect)

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