protostjärnans

Protostjärnan is a Swedish term that translates to "protostar" in English. A protostar is a celestial object that is in the early stage of star formation. It is a dense core of gas and dust within a collapsing nebula that has not yet begun nuclear fusion in its core. As the protostar accretes more material from its surrounding envelope, its mass and temperature increase. This accretion process typically generates significant amounts of radiation, making the protostar luminous, though not from fusion. Protostars are often embedded within dusty clouds, which can obscure them from visible light observation, making them easier to detect in infrared wavelengths. The duration of the protostellar phase varies depending on the mass of the star being formed, with more massive stars having shorter protostellar phases. Eventually, when the core temperature and pressure become high enough, nuclear fusion of hydrogen into helium ignites, marking the transition from protostar to a main-sequence star.