Definition
Stellar accretion refers to the inflow of ambient gas onto the surface of a star. During the process of star formation, accretion builds up the object to its final mass. The infalling gas is the interior portion of a dense core, a small molecular cloud that collapses under the influence of its own gravity. The object being built up in this manner is a protostar, and represents the first phase of stellar evolution. Some infalling gas impacts the protostar directly. Much of the gas, however, has sufficient angular momentum that it goes into orbit around the young star. The accreting gas thus creates a circumstellar disk. Matter spirals in through the disk onto the surface of the protostar. The remaining part of the disk eventually gives rise to planets.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2011 Springer-Verlag Berlin Heidelberg
About this entry
Cite this entry
Stahler, S. (2011). Accretion, Stellar. In: Gargaud, M., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-11274-4_1905
Download citation
DOI: https://doi.org/10.1007/978-3-642-11274-4_1905
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-11271-3
Online ISBN: 978-3-642-11274-4
eBook Packages: Physics and AstronomyReference Module Physical and Materials ScienceReference Module Chemistry, Materials and Physics