  A spectacular, transient mass-loss event in the hydrogen-deficient central
star of the planetary nebula Longmore 4 was discovered in 1992 by Werner et al.
During that event, the star temporarily changed from its normal PG 1159
spectrum to that of an emission-line [WCE] star. I have been monitoring the
spectrum of Lo 4 since 2003. Out of 31 spectra, two of them reveal mass-loss
outbursts similar to the one seen in 1992, showing that the phenomenon recurs.
I speculate on possible mechanisms for these unique outbursts, but emphasize
that we still have no fully convincing explanation.
