1. K. Takamizawa, Vsnet-Obs Circulation 18078, http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/obs18000/msg00078.html (1998).
2. P. Schmeer, Vsnet-Alert Circulation 4027, http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnetalert/msg04027.html (2000).
3. M. Uemura, T. Kato, K. Matsumoto, et al., Publ. Astron. Soc. Jpn. 52, L9 (2000).
4. N. N. Samus, IAU Circ., No. 7353 (2000).
5. A. Henden, vsnet-alert circulation 4060, http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnetalert/msg04060.html (2000).