Orion Nebula

Orion Nebula

The Orion Nebula is a diffuse nebula in the Milky Way situated south of Orion's Belt in the constellation of Orion, and is known as the middle "star" in the "sword" of Orion. It is one of the brightest nebulae and is visible to the naked eye in the night sky with an apparent magnitude of 4.0. It is 1,267.0 ± 5.4 light-years (388.5 ± 1.7 pc) away and is the closest region of massive star formation to Earth. M42 is estimated to be 25 light-years across. It has a mass of about 2,000 times that of the Sun. Older texts frequently refer to the Orion Nebula as the Great Nebula in Orion or the Great Orion Nebula.

Orion (constellation)

Orion is a prominent set of stars visible during winter in the northern celestial hemisphere. It is one of the 88 modern constellations; it was among the 48 constellations listed by the 2nd-century AD astronomer Ptolemy. It is named after a hunter in Greek mythology.

Nebula

A nebula is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral, or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regions, such as the Pillars of Creation in the Eagle Nebula. In these regions, the formations of gas, dust, and other materials "clump" together to form denser regions, which attract further matter and eventually become dense enough to form stars. The remaining material is then thought to form planets and other planetary system objects.

Orion Nebula

Proper noun

1. A diffuse nebula visible in the night sky below Orion's Belt; it is approximately 40 light years across. It is one of the brightest nebulae visible to the naked eye and is the closest region of stellar formation to Earth.