On the Subjective Color of Starlight and the Quality of Twilight Sensation

Abstract

A popular account is given to explain the subjective color of starlight. One’s predominant sensation while observing a star in the visual field is given by scotopic or ‘twilight’ vision, mediated by the rod cells of the eye. The hue of the characteristic rod sensation can be assessed. There is yet another influence on starlight color, however. Conditions for emergence of the Bezold-Br€ucke phenomenon are ideally fulfilled in the observation of starlight. A complete explanation of the color of starlight is provided by the effects of contrast on rod ‘blue’, together with the Bezold-Brücke phenomenon.