We present a photometric and spectroscopic study of a reddened type Ic supernova ( SN ) 2005at .
We report our results based on the available data of SN 2005at , including late-time observations from the Spitzer Space Telescope and the Hubble Space Telescope .
In particular , late-time mid-infrared observations are something rare for type Ib/c SNe .
In our study we find SN 2005at to be very similar photometrically and spectroscopically to another nearby type Ic SN 2007gr , underlining the prototypical nature of this well-followed type Ic event .
The spectroscopy of both events shows similar narrow spectral line features .
The radio observations of SN 2005at are consistent with fast evolution and low luminosity at radio wavelengths .
The late-time Spitzer data suggest the presence of an unresolved light echo from interstellar dust and dust formation in the ejecta , both of which are unique observations for a type Ic SN .
The late-time Hubble observations reveal a faint point source coincident with SN 2005at , which is very likely either a declining light echo of the SN or a compact cluster .
For completeness we study ground-based pre-explosion archival images of the explosion site of SN 2005at , however this only yielded very shallow upper limits for the SN progenitor star .
We derive a host galaxy extinction of A _ { V } \approx 1.9 mag for SN 2005at , which is relatively high for a SN in a normal spiral galaxy not viewed edge-on .