IL NUOVO CIMENTO VOL. 105 B, N. 4 Aprile 1990 A Fluid Source for the Kerr Metric (*). S. HAGGAG Science & Mathematics Center - P. O. Box 1070, Ta'if, Saudi Arabia (ricevuto il 30ttobre 1988; manoscritto revisionato ricevuto il 21 Novembre 1989) Summary. -- A fluid source for the Kerr metric is constructed. At the static limit, the metric tensor for the source reduces to a form equivalent to the Schwarzschild interior solution. Matter constituting the source is shown to satisfy the strong-energy condition, and hence the source is physically reasonable. PACS 04.20 - General relativity. The Kerr metric[i] is well known, being the simplest stationary axisym- metric solution to Einstein's vacuum field equations of general relativity, which is also asymptotically flat. It could thus represent the gravitational field due to a rotating body and hence its importance in relation to astrophysical studies of rotating stars is obvious. There have been many attempts to construct a source for the Kerr metric. Recently, such a source was given [2], which consisted of a spherical core and a thick shell. The metric in each region was shown to describe an anisotropic fluid with positive and negative principal pressures. More recently, another source of the same configuration was constructed [3], representing a nearly perfect fluid, viz. a fluid with positive principal pressures which are equal up to a certain order. The sources in [2, 3] have been shown to satisfy energy conditions and are thus physically reasonable. However, the metric components are given in a very complicated form, formidable to further investigation into other properties of the (*) To speed up publication, the author of this paper has agreed to not receive the proofs for correction. 25 - Il Nuovo Cimento B. 365