Norma Arm

The Norma Arm is a major spiral arm of the Milky Way galaxy. It lies between the Scutum-Centaurus Arm and the Outer Arm, and is located farther from the galactic center than the Sagittarius Arm.

The arm is named for the constellation Norma, in whose direction it is observed from Earth. While the term "arm" suggests a continuous structure, the Norma Arm, like other spiral arms in the Milky Way, is likely composed of segments of higher stellar density and gas clouds.

Observations of the Norma Arm are hindered by its location relative to Earth, which makes it difficult to observe through the dense dust and gas concentrated in the galactic plane. Nevertheless, radio astronomy and infrared observations have helped to reveal its structure and composition. Studies of neutral hydrogen and carbon monoxide have been crucial in tracing the arm's density and identifying regions of star formation.

The Norma Arm is believed to be significant in understanding the overall structure and dynamics of the Milky Way galaxy, contributing to the ongoing research into the processes that shape and maintain spiral galaxies.