Follow a book , follow an author

[DevMiMar]

Just an idea but I dont know if that is even possible (ActivityPub?) as it's not account related.
I would like
to follow a book (and followers will get a post if "something" happend with this book...comments..start reading...etc.)
to follow an author (and followers will get a post if "something" happend with a book related to this author...comments..start reading...etc.)

[jaschaurbach]

That'll be great!