An extremely X-ray luminous proto-Herbig Ae Be star in the Serpens star forming region

We present near-infrared spectra for the highly obscured, optically invisib le young stellar object EC 95 in the Serpens molecular cloud, from which we recently could detect strong X-ray emission with ROSAT. Its location in th e HR diagram suggests this object to be an extremely young(similar to 2 x 1 0(5) yr old) intermediate-mass (similar to 4 M.) star, which is most likely the progenitor of a B-type or early A-type main sequence star. The only re asonable explanation for its extremely strong Xray emission (L-X similar to 1.2 x 10(33) erg/sec) seems to be coronal, i.e. magnetic activity; this vi ew is also supported by the strong radio emission of EC 95. This is quite s urprising, since one usually does not expect a magnetic field on intermedia te-mass stars, which are thought to lack surface convection zones, the prer equisite for a solar-like dynamo effect. A possible explanation might be th at EC 95 currently goes through a short period of deuterium shell burning, which causes convection near the stellar surface and might give rise to a d ynamo effect and a corona.