**1. Introduction**

The Sun is the closest (by far) of the stellar objects we can study. Yet, we remotely sense it only, by means of recording electromagnetic spectra emitted from its activity. Remote sensing studies permit to analyze the Sun in many different perspectives, according to the types of spectra the instrument focus is. Thermodynamics, hydrodynamics applied to plasma with magnetic fields are all needed to study the radiative, convective, and exo-atmospheric conditions of the Sun energy transport. Stellar objects of different characteristics have been observed for ages by astronomers, and many physical theories have been developed relating observations and life cycles (i.e., HR diagram and equations of stellar structure, respectively). Stellar oscillations [1], spherical harmonics, and resonance patterns analysis belong to geophysics and are now in common use to study and classify stars.

More recently, scientists have been able to evolve geophysics techniques to reach within layers of the Sun. Seismology is now having a branch dedicated to the Sun: helioseismology. Magneto-convective analysis relies on remote sensing and physics, modeling, and inverse modeling. The Sun's core is in the process of nuclear fusion, where quantum physics applies. Atomic physics permits us to understand the life cycle of stars and their creation of atoms of different Z number depending on the type of star evolution as well as hydrostatic equilibrium conditions and environments. The Coulomb barrier and the Gamow peak involve both atomic physics and quantum statistics. Random walks taking 1 million years for a photon to leave the core to the radiative and arrive at the convective zone of the Sun are found from combined fields of physics and stochastic/Markovian modeling science.

Technological sciences such as supercomputing, applied experimental physics, engineering are also necessary to tackle complex modeling, simulation, and experiments. Astronomical engineering is particularly of importance in this case, on Earth and in orbit (space science/engineering) to gather remote sensing data. Lastly, theoretical mathematicians, physicists, and scientists have all had parts in developing the sciences used in the Sun analysis today, as the most fundamental of the sciences reverberate in the different bits of understanding found in the group of sciences that evolved from simple timing of and logging of visible events, to more complex instrumentation/analysis as observation sciences became more technological. A final question that comes to mind when analyzing electromagnetic interaction of magnetism such as the Zeeman effect is where is the electric part in the research on the Sun's electromagnetism. Is there magnetism alone only in the Sun?
