VRI CCD Photometric Observations of SN 1994I in M51

We present wide-band VRI photometry of supernova SN 1994I in M51 for the period April 5-May 30. Observations were carried out using a 51-cm reflector at Osaka Kyoiku University. The magnitudes were determined using a direct integration technique after removing the local sky background fitted with a quadratic surface. A nearby star (TB 135) was used as a reference star. The estimated accuracy of the results was within +/- 0.05 mag when the SN was brighter than 14 mag, while it was around +/- 0.1 mag when the SN became fainter. The brightness of the supernova declined steeply (about 0.1 mag per day) after reaching maximum brightnesses on April 8-9 (V band) and on April 10-11 (R and I bands). The rate of decline slowed down to about 0.03 mag per day about 20 d after the maximum. Our results are consistent with the classification of SN 1994I as a Type Ic event.