  Using HST/STIS, we have detected far-ultraviolet nuclear activity in the
giant elliptical galaxy NGC 1399, the central and brightest galaxy in the
Fornax I cluster. The source reached a maximum observed far-UV luminosity of
\~1.2 x 10e39 ergs/s in January 1999. It was detectable in earlier HST archival
images in 1996 (B band) but not in 1991 (V band) or 1993 (UV). It faded by a
factor of ~4x by mid-2000. The source is almost certainly associated with the
low luminosity AGN responsible for the radio emission in NGC 1399. The
properties of the outburst are remarkably similar to the UV-bright nuclear
transient discovered earlier in NGC 4552 by Renzini et al. (1995). The source
is much fainter than expected from its Bondi accretion rate (estimated from
Chandra high resolution X-ray images), even in the context of "radiatively
inefficient accretion flow" models, and its variability also appears
inconsistent with such models. High spatial resolution UV monitoring is a
valuable means to study activity in nearby LLAGNs.

Astrophysics