SIMBAD references

We report the discovery of two supernovae (SNe), SN 1999gw and SN 2001db, obtained within the framework of an infrared (2.1µm) monitoring campaign of Luminous Infrared Galaxies, aimed at detecting obscured supernovae. SN 2001db, extinguished by A_V≃5.5mag, is the first supernova discovered in the infrared that has received the spectroscopic confirmation. This result highlights the power of infrared monitoring in detecting obscured SNe and indicates that optical surveys probably miss a significant fraction of SNe, especially in obscured systems such as starburst galaxies. The preliminary estimate of SN rate in Luminous Infrared Galaxies is about an order of magnitude higher than that expected from optical surveys.