Pressure balances gravity (Figure 14.1 of Cosmic Perspective)

Visible light image of the Sun

Visible light image of the solar chromosphere and corona during a solar eclipse

Extreme ultraviolet Soho image of the Sun

Soft x-ray Trace image of the Sun

The solar interior

Venus transit (Solar Dynamics Observatory 2012)

Animation

Solar granulation driven by convection

Animation

Coronal loops

Animation

Animation

The Sun in X-rays

Animation

Coronal mass ejection

Animation

Aurora

Visible solar spectrum (400-700 nm)
(N.A.Sharp, NOAO/NSO/Kitt Peak FTS/AURA/NSF)

Hydrogen fusion by the proton-proton chain (Figure 14.8 of Cosmic Perspective)

An image of neutrinos from the Sun observed by the Super-Kamiokande neutrino observatory

Super-Kamiokande observatory

Neutrino image (whole sky, centered on Sun)

Doppler image of the Sun, showing 5 minute solar oscillations