I see some brokers show two panels for LSST alerts, one with difference photometry, and the other with forced photometry. I would assume the forced magnitude come from the flux of the diaForcedSource, while difference magnitude comes from the diaSource. As far as I understand, on a given date the only difference between these two should be detection or non-detection. Meaning that the event can be detected as a diaForcedSource while not being normally detected as a diaSource. However, I see that for a given date, there are small differences between the difference magnitude and the forced magnitude, does anyone know why is this?
Hi @pjpessi, it would be worth confirming with the brokers which measurements they are using, but the diaForcedSource measurement is forced at the DiaObject position, which may differ from the centroid of the diaSource detection, resulting in a slightly different flux value.