---
title: "Star"
id: "star"
project: "Zero-Gravity Exercise Routines Publication"
url: "https://hedronlabs.clickhelp.co/articles/zero-gravity-exercise-routines-publication/star"
updated: 2025-06-26T09:07:59Z
---

# Star

#  Star
 
A star is an [astronomical object](https://en.wikipedia.org/wiki/Astronomical_object) comprising a luminous [spheroid](https://en.wikipedia.org/wiki/Spheroid) of [plasma](https://en.wikipedia.org/wiki/Plasma_%28physics%29) held together by [self-gravity](https://en.wikipedia.org/wiki/Self-gravitation). The [nearest star](https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs) to [Earth](https://en.wikipedia.org/wiki/Earth) is the [Sun](https://en.wikipedia.org/wiki/Sun). Many other stars are visible to the naked eye at [night](https://en.wikipedia.org/wiki/Night_sky), but their immense distances from Earth make them appear as [fixed](https://en.wikipedia.org/wiki/Fixed_stars) points of light. The most prominent stars have been categorised into [constellations](https://en.wikipedia.org/wiki/Constellation) and [asterisms](https://en.wikipedia.org/wiki/Asterism_%28astronomy%29), and many of the brightest stars have [proper names](https://en.wikipedia.org/wiki/Proper_name). [Astronomers](https://en.wikipedia.org/wiki/Astronomer) have assembled [star catalogues](https://en.wikipedia.org/wiki/Star_catalogue) that identify the known stars and provide standardized [stellar designations](https://en.wikipedia.org/wiki/Stellar_designation). The [observable universe](https://en.wikipedia.org/wiki/Observable_universe) contains an estimated 10^22^ to 10^24^ stars. Only about 4,000 of these stars are visible to the naked eye, all within the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way) [galaxy](https://en.wikipedia.org/wiki/Galaxy).