Astrophysical plasma

When matter becomes sufficiently hot and energetic, it becomes ionized and forms a plasma. This process breaks matter into its constituent particles which includes negatively charged electrons and positively charged ions. These electrically charged particles are susceptible to influences by local electromagnetic fields. This includes strong fields generated by stars, and weak fields which exist in star forming regions, in interstellar space, and in intergalactic space. Similarly, electric fields are observed in some stellar astrophysical phenomena, but they are inconsequential in very low-density gaseous media.

Astrophysical plasma is often differentiated from space plasma, which typically refers to the plasma of the Sun, the solar wind, and the ionospheres and magnetospheres of the Earth and other planets.

Observing and studying astrophysical plasma

Plasmas in stars can both generate and interact with magnetic fields, resulting in a variety of dynamic astrophysical phenomena. These phenomena are sometimes observed in spectra due to the Zeeman effect. Other forms of astrophysical plasmas can be influenced by preexisting weak magnetic fields, whose interactions may only be determined directly by polarimetry or other indirect methods. In particular, the intergalactic medium, the interstellar medium, the interplanetary medium and solar winds consist of diffuse plasmas.