The sudden brightening of FU Ori, which led to the classification of an entirely new type of star known as FUor stars, has been attributed to the process of gravitational accretion – the same mechanism that aids in the formation of stars and planets.
Gravitational Accretion and FUor Stars
Gravitational accretion is a key process in the formation of stars and planets. When a cloud of gas and dust collapses under its own gravity, the material at the center begins to form a protostar. As the protostar grows, it continues to accumulate material from the surrounding disk, causing it to brighten over time.
The Sudden Brightening of FU Ori
In the case of FU Ori, the sudden brightening of the star was particularly dramatic. Normally, the process of gravitational accretion happens gradually, but in FU Ori, the accretion rate increased dramatically, causing the star to brighten by several magnitudes in just a few months. This sudden brightening led to the classification of FU Ori as a new type of variable star, known as an FUor star.
Implications and Significance
The study of FUor stars has provided valuable insights into the process of star formation and the role of gravitational accretion. These stars offer a unique window into the early stages of stellar evolution, and their sudden brightening events can shed light on the mechanisms that drive the accretion of material onto young protostars.