Venus and the Schroter effect

Dichotomy, or half-phase for Venus was predicted to be 6th January but due to the Schroter effect may appear late. This is a phenomenon in which the observed phase of Venus appears less than the predicted phase. As a result, dichotomy (half phase) occurs early at evening elongations, and late at morning elongations. The time difference between calculated and observed dichotomy is about a week. The effect was discovered by the German astronomer Johann Hieronymus Schröter (1745–1816). The cause may be that the region near the terminator is darker than the rest of the illuminated disk.

Here is a rather poor image of Venus from the window-sill this morning.


Here is the general view from this morning (9/1/2019). I didn’t manage this yesterday. Early risers can look forward to the Venus-Jupiter conjunction on 22nd January.

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