> They point out that nobody else on the planet seems to have seen this comet passing in front of the Sun, even though the nearest observatories in those days were just a few hundred kilometers away.
This is 1883 and noone else recorded seeing it? Even in all of mexico?
"That can be explained using parallax. If the fragments were close to Earth, parallax would have ensured that they would not have been in line with the Sun even for observers nearby. And since Mexico is at the same latitude as the Sahara, northern India and south-east Asia, it's not hard to imagine that nobody else was looking."
Is this realistic? Also would the time of day matter? If the sun was low to the horizon etc.
> The do say in the article about no-one seeing it;
"That can be explained using parallax ..."
> Is this realistic?
No. Even today not many observatories specialize in sun observations. It's not at all surprising that only one astronomer witnessed this, and it's a stretch to suggest the explanation that the observed object was therefore very close -- there are many more plausible explanations.
> Also would the time of day matter?
No, not for an object silhouetted against the sun. Consider this year's Venus transit -- everyone who could see the sun at the appointed time, also could see the transit.
This is 1883 and noone else recorded seeing it? Even in all of mexico?