Photon angular distance to SN 2017egm optical position as a function of time. Using the best-fit model of the ROI, the probability that a given photon is associated with the SN is illustrated by colors, while the size indicates the photon energy. The γ-ray time interval defined by the Bayesian block algorithm is illustrated with the shaded area. Coverage limitations due to the failure of one of the solar array rotator drives on Fermi resulted in the loss of approximately 18 days of data in March and April 2018.