I did not mark this as a spoiler because it says VERY LITTLE more than the description in the PBS schedule does. If you consider anything more than a program's title to be a spoiler, then don't read my last paragraph.
I found this interesting and did not mind watching for the entire length, but it supposedly contained SOME facts and archival footage and I would have preferred that those be noted somehow, maybe in an unobtrusive manner like a date on the bottom left of the screen during archival footage. As is, other than a few well-known facts like there is a James Webb space telescope (and presumably the other telescopes they mention do exist), one is just left to assume that ALL the rest of it is fictional. However, if you take it as total fiction merely based on actual scientific POSSIBILITY, but produced to "make you think" rather than just for pure entertainment, I'd say it accomplishes that.
I would actually like to see a little "making of" documentary about this documentary. Well, the genre of this is said to be documentary, but that doesn't sound quite right. However, "mockumentary" would not be appropriate either as it is not satire. Maybe a "conjecturmentary"?
As an example of "fact or fiction?", it is clearly fiction that there was an unnatural artifact for which they calculated its trajectory in order to have the James Webb space telescope look for a possible origin, BUT has that telescope actually seen such a sun and busted-planet configuration somewhere since it has been looking "everywhere"? If so, that would be irrelevant to this story line, but would be interesting to know!