The word "star" ultimately derives from the Proto-Indo-European root "h₂stḗr" also meaning star, but further analyzable as h₂eh₁s- ("to burn", … See more

The concept of a constellation was known to exist during the Babylonian period. Ancient sky watchers imagined that prominent … See more

Stars condense from regions of space of higher matter density, yet those regions are less dense than within a vacuum chamber. These regions—known as molecular clouds—consist mostly of hydrogen, with about 23 to 28 percent helium and a few … See more

Almost everything about a star is determined by its initial mass, including such characteristics as luminosity, size, evolution, lifespan, … See more

Historically, stars have been important to civilizations throughout the world. They have been part of religious practices, divination rituals, mythology, used for celestial navigation and … See more

Although stellar parameters can be expressed in SI units or Gaussian units, it is often most convenient to express mass, luminosity, and radii in solar units, based on the characteristics of the Sun. In 2015, the IAU defined a set of nominal solar values (defined as … See more

Stars are not spread uniformly across the universe but are normally grouped into galaxies along with interstellar gas and dust. A typical large … See more