An Etymological Dictionary of Astronomy and Astrophysics

A hypothetical, very rapidly → rotating star formed in the → metal-deficient conditions of the primordial → interstellar medium. The → first stars were probably spinstars, because the lack of metals leads to faster rotation velocities. Indeed → metal-poor stars are more compact than → metal-rich ones. Stars formed from a gas whose → metallicity is below 1/2000 of the → solar metallicity could attain rotation velocities of 500-800 km s^-1 (see also → Population III star). Rotation triggers → mixing processes inside the star, leading to the production of important quantities of ¹⁴N, ¹³C, and ²²Ne (Maeder & Meynet 2012, and references therein). The production of primary ²²Ne has an important impact on the → s-process  → nucleosynthesis in spinstars compared to non-rotating stars. This increases by orders of magnitude the s-process → yields of → heavy elements. Spinstars would therefore have strongly influenced the properties and appearance of the first galaxies that formed in the → Universe (See G. Meynet et al. 2009, arXiv:0709.2275; C. Chiappini, 2013, Astron. Nachr. /AN 334, No. 6, 595 and references therein).

See also: → spin; → star.