Photometry of SN 2002bo with template image subtraction

VRI photometry of the type Ia supernova 2002bo is presented. This SN exploded in a dusty region of the host galaxy NGC 3190, thus, subtraction of a template frame was necessary to obtain reliable photometry. We used a template frame of NGC 3190 taken during the course of our galaxy imaging project, fortunately, just a few days before SN 2002bo was discovered. The aim of this project is to collect template frames of nearby galaxies that are potential hosts of bright SNe. Subtraction of pre-SN images helped us to exclude the background light contamination of the host galaxy. The maximum occurred at JD 2 452 346, with maximal V brightness of 13 m58. MLCS analysis led to T0(B) = JD 2 452 346.1 ±0.8 (fiducial B-maximum), E(b-V),=0.m24 ±0m0.2, (mu)0=32.46 ±0.06, (delta)=-0.14 ±0.04 . E(B-V)=0.m24(2) indicates a significant extinction in the host galaxy as the galactic reddening is negligible toward NGC 3190. The accepted value of (delta)indicates that SN 2002bo was a slightly overluminous SN by about 0 m14 relative to fiducial SN type Ia. The distance turned out to be 31.0 ±3 Mpc. In addition, the heavily obscured SN 2002cv was also detected on the I frame taken on JD 2 452 434 (June 8, 2002), and a variable star is found in the field, very close to the host galaxy.