  Using the Very Long Base Array, we observed the young stellar object EC 95 in
the Serpens cloud core at eight epochs from December 2007 to December 2009. Two
sources are detected in our field, and are shown to form a tight binary system.
The primary (EC 95a) is a 4--5 $M_\odot$ proto-Herbig AeBe object (arguably the
youngest such object known), whereas the secondary (EC 95b) is most likely a
low-mass T Tauri star. Interestingly, both sources are non-thermal emitters.
While T Tauri stars are expected to power a corona because they are convective
while they go down the Hayashi track, intermediate-mass stars approach the main
sequence on radiative tracks. Thus, they are not expected to have strong
superficial magnetic fields, and should not be magnetically active. We review
several mechanisms that could produce the non-thermal emission of EC 95a, and
argue that the observed properties of EC 95a might be most readily interpreted
if it possessed a corona powered by a rotation-driven convective layer. Using
our observations, we show that the trigonometric parallax of EC 95 is $\pi$ =
2.41 $\pm$ 0.02 mas, corresponding to a distance of 414.9$^{+4.4}_{-4.3}$ pc.
We argue that this implies a distance to the Serpens core of 415 $\pm$ 5 pc,
and a mean distance to the Serpens cloud of 415 $\pm$ 25 pc. This value is
significantly larger than previous estimates ($d$ $\sim$ 260 pc) based on
measurements of the extinction suffered by stars in the direction of Serpens. A
possible explanation for this discrepancy is that these previous observations
picked out foreground dust clouds associated with the Aquila Rift system rather
than Serpens itself.
