AstroNote 2022-239

We report on the detection of two infrared transient candidates in JWST observations of Abell 2744, AT 2022aaih, and AT 2022aaii. Both candidates were discovered in NIRCam observations in Cycle 1 ERS Program 1324 (PI: Tommaso Treu) via image subtraction with an earlier epoch of the same program. The first epoch was taken on MJD 59759, and the second epoch was taken on MJD 59894, a separation of 135 days. We report magnitudes for each object by performing simple aperture photometry, and the measurements are relative to current JWST photometric calibration estimates.

The first candidate, AT 2022aaih, is found at RA 3.49372, DEC -30.3254358. This source is detected in filters F090W, F115W, F150W, F200W, F277W, F356W, and F444W at AB magnitudes of 27.87 ± 0.06, 26.80 ± 0.02, 26.06 ± 0.01, 25.85 ± 0.01, 25.98 ± 0.01, 26.58 ± 0.02, 26.62 ± 0.02 respectively. 

The second source, AT 2022aaii, is detected at coordinates of RA 3.5228717, DEC -30.3512897, and only in F277W, F356W, and F444W, as it is between detector channels in the shorter wavelength filters. This source has AB magnitudes of 27.44 ± 0.04, 27.87 ± 0.06, and 28.13 ± 0.07. The limiting magnitude of the observation in these filters are determined to be ~28.5 mag at the 0.1 uncertainty level. The exposure times for these filters were 11144.764 (s), 16491.684 (s), and 65966.736 (s) respectively.