SIMBAD references

P. Woudt, University of Cape Town (UCT); and P. Charles and I. C. Shih, University of Southampton, report that, following the INTEGRAL detection of renewed hard x-ray activity in the blackhole transient XTE J1550-564, they obtained high-speed photometry of the optical counterpart (Jain et al. 2001, Ap.J. 554, L181) with the South African Astronomical Observatory 1.9-m telescope (+ UCT CCD) during 25 min on Mar. 27. The object appeared at V about 18 (close to its maximum during the 2000 outburst) and it displays significant variability on timescales of 1-2 min, including a flare of about 0.5 mag lasting < 20 s. Further observations of this microquasar at infrared and radio observations are strongly encouraged.