They study the Sun's structure, composition, and activity, including:

* Solar flares and coronal mass ejections: These powerful bursts of energy can affect Earth's atmosphere and technology.

* The Sun's magnetic field: This field controls many aspects of the Sun's activity.

* The Sun's interior: This is where nuclear fusion takes place, producing the Sun's energy.

* The Sun's evolution: They study how the Sun has changed over time and will continue to change in the future.

Other related fields include:

* Astrophysicist: Studies the physics of the Universe as a whole, including stars, galaxies, and the cosmic background radiation.

* Helioseismologist: Studies the Sun's interior by observing its vibrations.

* Space weather scientist: Studies the effects of the Sun on Earth and other planets.