Optical and Infrared Photometry of the Nearby Type Ia Supernova 2001el
  We present well sampled optical (UBVRI) and infrared (JHK) light curves of the nearby (~18.0 Mpc) Type Ia supernova SN 2001el, from 11 days before to 142 days after the time of B-band maximum. The data represent one of the best sets of optical and infrared photometry ever obtained for a Type Ia supernova. Based on synthetic photometry using optical spectra of SN 2001el and optical and infrared spectra of SN 1999ee, we were able to devise filter corrections for the BVJHK photometry of SN 2001el which to some extent resolve systematic differences between SN 2001el datasets obtained with different telescope/filter/instrument combinations. We also calculated V minus infrared color curves on the basis of a delayed detonation model and showed that the theoretical color curves match the unreddened loci for Type Ia SNe with mid-range decline rates to within 0.2 mag. Given the completeness of the light curves and the elimination of filter-oriented systematic errors to some degree, the data presented here will be useful for the construction of photometric templates, especially in the infrared. On the whole the photometric behavior of SN 2001el was quite normal. The second H-band maximum being brighter than the first H-band maximum is in accord with the prediction of Krisciunas et al. (2000) for Type Ia SNe with mid-range decline rates. The photometry exhibits non-zero host extinction, with total A_V = 0.57 +/- 0.05 mag along the line of sight. NGC 1448, the host of SN 2001el, would be an excellent target for a distance determination using Cepheids. 
Kevin Krisciunas, Nicholas B. Suntzeff, Pablo Candia, Jose Arenas,   Juan Espinoza, David Gonzalez, Sergio Gonzalez, Peter A...