We find the supergravity solution sourced by a supertube: a (1/4)-supersymm
etric D0-charged IIA superstring that has been blown up to a cylindrical D2
-brane by angular momentum. The supergravity solution captures all essentia
l features of the supertube, including the D2-dipole moment and an upper bo
und on the angular momentum: violation of this bound implies the existence
of closed timelike curves, with a consequent ghost-induced instability of s
upertube probes.