What was the decisive second visual clue that confirmed the object was moving relative to the background?
Answer
Clear positional shift against fixed background stars over several nights
The second clue was motion; Herschel meticulously recorded that the disc-shaped object shifted its position relative to the seemingly unmoving background stars over several nights.
Related Questions
In what month and year did William Herschel discover the new celestial body?What was Herschel's primary systematic work at the time of his discovery?What specific instrument did Herschel use to spot the object on March 13, 1781?What was the first critical visual clue that suggested the object was not a distant star?What was the decisive second visual clue that confirmed the object was moving relative to the background?What celestial body did Herschel initially hypothesize the object might be, based on initial visual evidence?What mathematical evidence ultimately confirmed the object's status as a planet over a comet?What name did Herschel initially propose for the seventh planet he discovered?What was the primary optical advantage of Herschel's reflecting telescopes compared to early refracting telescopes?Before Herschel's discovery, how many planets (excluding Earth) were thought to constitute the solar system?