What is Surface gravity?
The '''surface gravity''', ''g'', of an [[astronomy|astronomical]] or other [[object]] is the [[gravity|gravitational]] [[acceleration]] [[wikt:experience|experience]]d at its [[surface]]. The surface gravity may be thought of as the acceleration caused by the gravity experienced by a hypothetical test particle which is very close to the object's surface and which, in order not to disturb the system, has negligible mass. Surface gravity is measured in units of [[acceleration]], which, in the [[SI]] system, are meters per second squared. It may also be described as a multiple of the [[Earth]]'s [[gravity]], ''g''&nbsp;=&nbsp;9.80665&nbsp;m/s<sup>2</sup>.<ref>p. 29, [http://physics.nist.gov/Document/sp330.pdf The International System of Units (SI)] {{Webarchive|url=https://web.archive.org/web/20071031165844/http://physics.nist.gov/Document/sp330.pdf |date=2007-10-31 }}, ed. Barry N. Taylor, NIST Special Publication 330, [[2001]].</ref> In [[astrophysics]], the surface gravity may be expressed as log ''g'', which is obtained by first expressing the gravity in [[Centimetre gram second system of units|cgs units]], where the unit of acceleration is [[centimeter]]s per second squared, and then taking the base 10 [[logarithm]].<ref>{{cite web | last = Smalley | first = B. | date = July 13, 2006 | url =http://www.astro.keele.ac.uk/~bs/publs/review_text.html | title =The Determination of T''eff'' and log ''g'' for B to G stars | publisher = Keele University | accessdate = 2007-05-31 }}</ref> ==References== {{reflist}} ==Other websites== * [http://farside.ph.utexas.edu/teaching/301/lectures/node152.html Newtonian surface gravity] {{physics-stub}} [[Category:Astrophysics]]