Ø4

Ø4, also known as O4 or Omicron 4, is a star located in the constellation of Orion, approximately 1,340 light-years away from Earth. It is part of the Orion Nebula, a prominent diffuse nebula situated in the Orion constellation's "sword" region. The star is a member of the Trapezium cluster, a group of young, hot, massive stars that are gravitationally bound to each other.

Ø4 is a multiple star system, consisting of at least four components. The primary component, Ø4 A, is a hot, blue main-sequence star of spectral type O7V, with a mass approximately 30 times that of the Sun. It is the most massive and luminous star in the Trapezium cluster. The other components, Ø4 B, C, and D, are also hot, massive stars, with spectral types ranging from B0V to B3V.

The Ø4 system is notable for its high luminosity and strong stellar winds, which have a significant impact on the surrounding Orion Nebula. The intense ultraviolet radiation from Ø4 and other stars in the Trapezium cluster ionizes the nebula's gas, causing it to emit light and creating the characteristic glow of the Orion Nebula. Additionally, the stellar winds from these stars shape the nebula's structure and contribute to its ongoing evolution.

Ø4 is a relatively young star system, with an estimated age of less than 1 million years. It is still in the process of forming and evolving, and its future evolution will be influenced by its high mass and the dynamics of the Trapezium cluster. The study of Ø4 and other stars in the Orion Nebula provides valuable insights into the processes of star formation and the early evolution of massive stars.