4.1 The young solar photosphere: Large, polar spots
  4.1.1 Doppler imaging of young solar analogs
  4.1.2 Polar spots
 4.2 Coronal structure of the young Sun
  4.2.1 Magnetic loop models and active regions
  4.2.2 Inferences from coronal density measurements
  4.2.3 Inferences from rotational modulation
  4.2.4 Inferences from eclipses
  4.2.5 Photospheric-field extrapolation to the corona
  4.2.6 Summary on coronal structure
 4.3 Activity cycles in the young Sun
  4.3.1 Starspot cycles of solar analogs
  4.3.2 X-ray cycles of solar analogs