What is what is one advantage of a primary source has over a secondary source

One advantage a primary source has over a secondary source is the fact that the primary source represents a viewpoint of an individual who was there and actually experienced the event in question.

For example, a journal entry from a delegate who attended the Constitutional Convention is much more advantageous than a secondary source on this topic. This is due to the fact that a journal entry would give more insight into what the delegates were thinking at the time and would allow for how the events unfolded from a personal perspective. When we read secondary sources, they often leave out this human element of it and tend to rely solely on using facts and laws developed as a result of this convention.

it would take 95 years for that supernova to be visible on earth, so the year would be about 2113. i hope i did my calculation right.