IS THE SOLAR CORE ROTATING FASTER OR SLOWER THAN THE ENVELOPE

The Sun is not a rigid body and it is well known that its surface rota tion is differential, the polar regions rotating substantially slower than the equator. This differential rotation has been demonstrated by helioseismology to continue down to the base of the convective zone, b elow which it becomes closer to a rigid body rotation. Far deeper, ins ide the energy generating core, the rotation has generally been assume d to be much faster, keeping memory of the presumably high speed of th e young Sun. However, several recent results of helioseismology have d ecreased this likelihood more and more, so that the core rotation coul d be suspected to be only marginally, or even not at all faster than t he envelope. Certain results would even imply a core rotation slower t han the envelope, an interesting but unlikely possibility. We present here a complete analysis of the rotational splitting of the low degree modes measured in three different time series obtained in 1990, 1991, and 1992 by the IRIS full-disk network. With a time of integration sl ightly longer than 4 months, the splitting has been measured by 4 diff erent global methods on 42 doublets of e = 1, 35 triplets of e = 2, an d 30 quadruplets of e = 3. With a high level of confidence, our result is consistent with a rigid solar core rotation.