What was the first critical visual clue that suggested the object was not a distant star?
Answer
It possessed a measurable disc shape
Stars appear as perfect, unresolved points of light, but Herschel noted that this object had a measurable disc, suggesting it was a nearer, reflecting body like a planet or nebula.
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?