Solar Physics

KIPAC members who are part of the Stanford Solar Observatories Group use data from several Earth-bound and space-based instruments to conduct observational and theoretical research on the physics of the Sun. The Solar Group (for short) focuses research efforts on dynamic solar processes that can have real-world consequences for the Earth, such as solar flares and coronal mass ejections (CMEs) that can damage satellites and disrupt communications.

The Solar Group studies the structure and dynamics of the Sun with a variety of instruments, including several for which the Solar Group led by KIPAC professor Philip Scherrer played major roles in development and operations.

  • The Michelson Doppler Imager (MDI) instrument on the Solar and Heliospheric Observatory (SOHO) provided magnetic and helioseismic data during 15 years of service. The MDI data set, part of an extensive solar data archive at Stanford, continues to be invaluable for understanding the Sun.
  • The successor to MDI, the Helioseismic and Magnetic Imager (HMI), was launched in February 2010 aboard the Solar Dynamics Observatory (SDO). It was declared operational mid-May of that year and continues to produce helioseismic and magnetic field observations at high resolution each 45 seconds.
  • SDO also carries the Atmospheric Imaging Assembly (ALA), developed in collaboration with the Lockheed Martin Solar and Astrophysics Laboratory (LMSAL), with LMSAL as lead. ALA provides continuous observations of the solar corona and chromosphere in extreme ultraviolet.
  • The Solar Group also operates the Wilcox Solar Observatory (WSO) in the hills south of campus. WSO produces daily low-resolution maps of the Sun's magnetic field, along with observations of solar surface motions, and has done so since 1976, resulting in a treasure trove of data about solar variability over time. 

In addition, Scherrer is a co-investigator of the Polarametric and Helioseismic Imager, an instrument on the ESA/NASA Solar Orbiter which launched February 9, 2020, while KIPAC staff scientist Todd Hoeksma is a co-investigator of the Solar Orbiter's Magnetometer.

MDI and HMI provide helioseismology and magnetic field data with which the group studies the solar interior and atmosphere—both local dynamics and the global structure of the Sun. Many analysis and modeling opportunities help exploit these unique observations. Simulations are increasingly important. Predicting solar sources of space weather is a long-term research goal.

Please see the Stanford Solar Observatory Group's website for detailed information.