2005IAUC.8520....3H

M. Hamuy, C. Contreras, S. Gonzalez, and W. Krzeminski, Carnegie Supernova Project, report that the type-Ic SN 2005bf (cf. IAUC 8507, 8509) is undergoing an unusual photometric behavior, brightening from u' = 18.69 on Apr. 7 to u' = 17.90 on Apr. 13, and declining to u' = 18.61 on Apr. 21, after which it has been re- brightening (reaching u' = 17.92 on Apr. 29). Similar photometric behaviors have been observed in the g', r', and i' bands, although the dip is less pronounced at longer wavelengths. On Apr. 29, g' = 16.91, r' = 16.71, and i' = 16.76. The light curves are posted at http://csp1.lco.cl/~cspuser1/images/OPTICAL_LIGHT_CURVES/SN05bf.html. Additional photometric and spectroscopic observations are urged.