JWST Photometric Time-delay and Magnification Measurements for the Triply Imaged Type Ia "SN H0pe" at z=1.78

Supernova (SN) SN H0pe is a gravitationally lensed, triply imaged, Type Ia SN (SN Ia) discovered in James Webb Space Telescope imaging of the PLCK G165.7+67.0 cluster of galaxies. Well-observed multiply imaged SNe provide a rare opportunity to constrain the Hubble constant (H-0), by measuring the relative time delay between the images and modeling the foreground mass distribution. SN H0pe is located at z = 1.783 and is the first SN Ia with sufficient light-curve sampling and long enough time delays for an H-0 inference. Here we present photometric time-delay measurements and SN properties of SN H0pe. Using JWST/NIRCam photometry, we measure time delays of Delta t(ab) = -116.6(-9.3)(+10.8) observer-frame days and Delta t(cb) = -48.6(-4.0)(+3.6) observer-frame days relative to the last image to arrive (image 2b; all uncertainties are 1 sigma), which corresponds to a similar to 5.6% uncertainty contribution for H-0 assuming 70 km s(-1) Mpc(-1). We also constrain the absolute magnification of each image to mu(a) = 4.3(-1.8)(+1.6), mu(b) = 7.6(-2.6)(+3.6), mu(c) = 6.4(-1.5)(+1.6) by comparing the observed peak near-IR magnitude of SN H0pe to the nonlensed population of SNe Ia.