SweetSpot is a three-year National Optical Astronomy Observatory (NOAO)
Survey program to observe Type Ia supernovae (SNe Ia) in the smooth Hubble flow
with the WIYN High-resolution Infrared Camera (WHIRC) on the WIYN 3.5-m
telescope. We here present data from the first half of this survey, covering
the 2011B-2013B NOAO semesters, and consisting of 493 calibrated images of 74
SNe Ia observed in the rest-frame near-infrared (NIR) from 0.02<z<0.09.
Because many observed supernovae require host galaxy subtraction from templates
taken in later semesters, this release contains only the 186 NIR (JHKs​) data
points for the 33 SNe Ia that do not require host-galaxy subtraction. The
sample includes 4 objects with coverage beginning before the epoch of B-band
maximum and 27 beginning within 20 days of B-band maximum. We also provide
photometric calibration between the WIYN+WHIRC and Two-Micron All Sky Survey
(2MASS) systems along with light curves for 786 2MASS stars observed alongside
the SNe Ia. This work is the first in a planned series of three SweetSpot Data
Releases. Future releases will include the full set of images from all 3 years
of the survey, including host-galaxy reference images and updated data
processing and host-galaxy reference subtraction. SweetSpot will provide a
well-calibrated sample that will help improve our ability to standardize
distance measurements to SNe Ia, examine the intrinsic optical-NIR colors of
SNe Ia at different epochs, explore nature of dust in other galaxies, and act
as a stepping stone for more distant, potentially space-based surveys.Comment: Published in AJ. 10 tables. 11 figures. Lightcurve plots included as
a figureset and available in source tarball. Data online at
http://www.phyast.pitt.edu/~wmwv/SweetSpot/DR1_data