We present VRIJHK photometry , and optical and near-infrared spectroscopy , of the heavily extinguished Type Ia supernova ( SN ) 2002cv , located in NGC 3190 , which is also the parent galaxy of the Type Ia SN 2002bo .
SN 2002cv , not visible in the blue , has a total visual extinction of 8.74 \pm 0.21 mag .
In spite of this we were able to obtain the light curves between -10 and +207 days from the maximum in the I band , and also to follow the spectral evolution , deriving its key parameters .
We found the peak I -band brightness to be I _ { max } = 16.57 \pm 0.10 mag , the maximum absolute I magnitude to be M ^ { max } _ { I } = -18.79 \pm 0.20 , and the parameter \Delta m _ { 15 } ( B ) specifying the width of the B -band light curve to be 1.46 \pm 0.17 mag .
The latter was derived using the relations between this parameter and \Delta m _ { 40 } ( I ) and the time interval \Delta t _ { max } ( I ) between the two maxima in the I -band light curve .
As has been found for previously observed , highly extinguished SNe Ia , a small value of 1.59 \pm 0.07 was obtained here for the ratio R _ { V } of the total-to-selective extinction ratio for SN 2002cv , which implies a small mean size for the grains along the line of sight toward us .
Since it was found for SN 2002bo a canonical value of 3.1 , here we present a clear evidence of different dust properties inside NGC 3190 .