FORMATION OF THE NEBULAR COMPLEX N-11 IN THE LARGE MAGELLANIC CLOUD

N 11, the second largest nebula of the LMC, is formed of a large bubbl e surrounded by 9 bright nebulae and filaments. We have observed this nebular complex with a scanning Fabry-Perot interferometer at H alpha and [OIII] 5007 wavelengths. The kinematics of this field agrees with the results of the stellar content and of the molecular studies, and s hows that such a structure can be the consequence of a sequential star formation. The elements of this result are deduced from the energetic input inside the ionized gas by the stellar winds of the associations LH9 and LH10. The evaluated dynamical lifespan of small nebular entit ies associated with the more massive stars of LH10, are found signific antly shorter than for the by the association LH9. Therefore sequentia l star formation can be triggered at the shock boundaries of the nebul a excited by an OB association in a time scale shorter than previously found, and of at most a few 10(6) yrs. It thus leads to the evidence for a new class of giant bubble, designated as ''ring of HII regions'' bubble with several distinctive characteristics. It is discussed that the bubbles of this type are formed by sequential star formation over time scales shorter than previously found for some superbubbles.