Solar Neighborhood

Synonyms

Solar cylinder; Solar vicinity

Keywords

Chemical elements, exoplanets, Milky Way, stellar populations, Sun

Definition

The Solar neighborhood is the space associated with a cylinder centered at the Sun and perpendicular to the Milky Way disk. This Solar Cylinder is located at ∼8 kpc from the Galactic center, with a radius of 1 kpc. Hence, the Solar vicinity includes diverse physical entities that belong to the Galactic disk and halo, such as planets; stars of different masses, ages, and evolutionary stages, interstellar medium and HII regions, amongst others.

Overview

The Solar neighborhood contains mostly baryonic matter (stars and gas); the amount of dark matter is negligible inside it. The total mass surface density is roughly 50 M_⊙ pc², of which the stars take 80% and 20% is in gaseous material.

The Solar cylinder contains two main structures, first, a disk componentwhere approximately 95% of the total mass is found in Population I stars embedded in metal-rich gas. They...