Disentangle camera-fixed foreground light from Moon-associated light

Determine whether the signal measured on the dark side of the Moon originates from light fixed to the camera, light associated with the Moon, or a combination of both.

Background

The dark-side lunar signal scales with exposure time and is most naturally interpreted as foreground light entering through the lens or spacecraft window. However, the Moon remained nearly fixed on the detector between the two exposures, preventing the available image comparison from separating detector-fixed illumination from light associated with the Moon. Resolving this ambiguity would improve the zero-point subtraction and the interpretation of faint F-corona profiles.

References

Because the Moon was almost fixed on the detector, however, light fixed to the camera and light associated with the Moon cannot be distinguished in this way.

— Revisiting the Optical F-corona from the Artemis II Total Solar Eclipse with RAW Data: How Far Can Consumer JPEG Images Be Trusted for Astronomical Photometry?  (2610.20194 - Tsumura et al., 14 Oct 2026) in Section 3.5, “Zero Point and Stray Light”