KATO, Taichi, D. Sc. (Kyoto Univ.), Astrophysics

   Scientific chief of the VSNET (http://www.kusastro.kyoto-u.ac.jp/vsnet/),
the best-renowned, pioneering international collaboration network on
transient objects and variable stars.  Besides our own observations
at Kyoto University, this network is continuously contributed by professional
and amateur astronomers with world-wide distribution, and plays a role
as one of the primary centers for transient object astronomy.  The main
research area includes cataclysmic variables, optical time variation of
black-hole binaries, novae, supernovae, blazars, gamma-ray bursts, and
other exotic classes of variable stars.  The most recent achievements,
conducted in collaboration with the VSNET members, include the discovery
of a totally unexpected giant optical outburst of the Galactic microquasar
V4641 Sagittarii, rapid optical fluctuations and optical flashes of the
same object, world most intensive campaign on the 2001 outburst of the
dwarf nova WZ Sagittae, comprehensive studies of ultrashort period
cataclysmic variables and their associated superhumps, and the detection
of early-stage variations in two gamma-ray burst afterglows GRB 021004
and GRB 030329.  The rapid optical fluctuations and optical flashes
in black-hole binaries, led by the discovery of the VSNET team,
is now being recognized as a promising tool for visualizing the inner
accretion flow close to a black hole.  These breaking news are continously
provided on the VSNET mailing lists and website, as well as a continous
stream of papers in major professional journals.

Recent representative works:

"Structure in the early afterglow light curve of the $\gamma$-ray burst
of 29 March 2003",
M. Uemura, T. Kato, R. Ishioka, H. Yamaoka, B. Monard, D. Nogami,
H. Maehara, A. Sugie, S. Takahashi,
Nature, 423, 843 (2003)

"Discovery of a Short Plateau Phase in the Early Evolution of a Gamma-Ray
Burst Afterglow",
M. Uemura, T. Kato, R. Ishioka, H. Yamaoka,
Publication of the Astronomical Society of Japan, 55, L31 (2003)

"Rapid Optical Fluctuations in the Black Hole Binary V4641 Sagittarii",
M. Uemura, T. Kato, R. Ishioka, K. Tanabe, S. Kiyota, B. Monard,
R. Stubbings, P. Nelson, T. Richards, C. Bailyn, R. Santallo,
Publication of the Astronomical Society of Japan, 54, L79 (2002)

"Discovery of Extremely Large-Amplitude Quasi-Periodic Photometric
Variability in WC9-Type Wolf-Rayet Binary, WR 104",
T. Kato, K. Haseda, H. Yamaoka, K. Takamizawa,
Publication of the Astronomical Society of Japan, 54, L51 (2002)

"On the Origin of Early Superhumps in WZ Sge-Type Stars",
T. Kato,
Publication of the Astronomical Society of Japan, 54, L11  (2002)