My interests are gravitational lensing, search for extra-solar planets
through microlensing, dark matter, planetary nebulae, and gamma-ray bursts.
I am a leading member of the PLANET (Probing Lensing Anomalies NETwork)
collaboration, where we use a network of 4 telescopes for round-the-clock
monitoring of on-going microlensing events. Currently, this is the only
method sensitive to detection of earth-size planets around normal stars, the
probability of detecting Jupiter-like planets being 
15%. We have
monitored about 23 events so far, and have detected three binary and
'extended source' anomalies. We observed with HST the first spatially-resolved
host-galaxy of GRB 970228. We have detected the spectacular bipolar morphology
of the 'stingray nebula' which, having transited from a star to a nebula
within the last 40 years, is the youngest known PN (to appear in Nature).