- Friday, September 29, 2017
- 3:30 PM–5:00 PM
- Science Building Classroom 110
Some of the latest discoveries about our Sun and the instruments designed to study it.
Speaker: 2017 Calvin College Distinguished Alumni Award recipient Dr. J. Todd Hoeksema '78, Senior Research Scientist W. H. Hansen Experimental Physics Lab, Stanford University
Thankfully the Sun is a reliable and steady source of energy, but when observed carefully, variability on time scales of milliseconds to millennia reveals much about our nearest star. The more familiar photosphere, where dark sunspots appear on an irregular 11-year cycle, is very photogenic, but how can images be turned into measurements? Sound waves detectable at the solar surface penetrate the interior and reveal physical conditions far below. Space-based ultraviolet instruments measure the dynamic high-temperature solar atmosphere. Special telescopes sensitive to polarized light sense the magnetic field, where energy stored above active regions causes flares and coronal mass ejections. How predictable is this space weather that can create hazardous conditions for life and society here on Earth?