I was trying to write something about Osamu Dazai, I know that for mangakas we use 先生, but usually celebrities' names are mentioned without any honorifics.
1 Answer
You'd have to consider the perspective in which you view this person yourself. Wikipedia and other such articles will not refer to a person with a suffix because Wikipedia or encyclopedias in general as neutral sources of information do not have such a perspective.
If you yourself met this person, or wanted to describe or talk about this person to someone else, think of it from your point of view.
For example, the general standard in Japan for respect is to utilize a title for a person if they have it.
If the person is someone you stand to learn something from, and is essentially a master of their trade, they are essentially 先生｛せんせい｝. You should also use this if this person is a professor or doctor of some sort.
If they are someone you respect, use -さん.
If they are someone you idolize, use -様｛さま｝.
Or, in other words, using these suffixes to refer to these people definitely exposes your personal opinion of these people, which is counter-intuitive if your goal is to write something informational about someone. However, if you don't use a suffix when speaking with them, it's not polite at all and implies a very close and personal relationship with them.