GX 339-4: back to life
  We report preliminary results of a RossiXTE campaign on the 2002 outburst of the black-hole candidate GX 339-4. We show power density spectra of five observations during the early phase of the outburst. The first four power spectra show a smooth transition between a Low State and a Very High State. The fifth power spectrum resembles a High State, but a strong 6 Hz QPO appears suddenly within 16 seconds. 
T. Belloni, E. Nespoli, J. Homan (Osservatorio Astronomico di Brera,   Merate, Italy), M. van der Klis (Astronomical Institu...