Telescope Reviews: Discovery of Uranus

I wonder at times how ancient observers missed Uranus and Vesta, both of which can be naked-eye visible (did it once myself on Uranus). Probably because they were not keeping such accurate tabs after all.
- dim stars were usually not recorded. Almagest, Antiquity's answer to Uranometria 2000, had 1022 stars recorded (I'm not that freakish, I had to look that up; the original Uranometria in 1603 had 1,200; Flamsteed's catalog had less than 3,000.
- if there was a Brian Marsden in 1,590, the number of observers who had the capacity to get in touch with him was much smaller than today.

Case in point: before the 19th century, there is almost no record of "modest" novae - we have Chinese and Precolumbian observations of supernovae, but no record of mag 4-5 events.

However I believe they would not have recorded it:
- .08° is very close, about 5'. Most people cannot distinguish stars less than 2' apart; here we are talking about a conjunction with Venus, which because of its glare has an "apparent" size in the sky which is quite large and would wash out any mag 5.9 object
- having a Venus-Mars conjunction usually means having these objects very close to the sun (Venus is never far anyway) so the background sky would have been too bright to see Uranus (maybe your sources can tell you what was the elongation, and to what extent the conjunction was observable)

So my belief is that this conjunction would have been the worst possible moment for a naked-eye observation of Uranus.

A luckier moment would have been Uranus showing up as an "intruder" close to an asterism observers were familiar with, such as the Pleiades.

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Matt
CI700 mount with various scopes on top.