A, of course.
Non fiction isn't all about facts, it can also border on figments of your imagination. Nevertheless ASTRONOMY and ASTROLOGY both have a spot within the wide world of non fiction.
Astronomy is a natural science that deals with the study of celestial objects; the physics, chemistry, and evolution of such objects; and phenomena that originate outside the atmosphere of Earth.
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world.
Still got trouble telling the two apart?
When people ask you your "sign"- that's Astrology. [...] Not to be confused with Astronomy, the bad-ass science of the universe.
See, the two couldn't be further apart ... or maybe not?
Astrology and Astronomy were archaically one and the same discipline, and were only gradually recognized as separate in Western 17th century philosophy.
Astrology is thought to be both a science and an art. It claims scientific status because it requires mathematics and an understanding of Astronomy. It is an art because interpretation is necessary to bring the different aspects together and formulate an idea of the individual's character traits and tendencies.
Curious? Find out more about Asimov's work on Goodreads.
The most exciting phrase to hear in science, the one that heralds the most discoveries, is not "Eureka!" (I found it!) but "That's funny ..."
You'll find non fiction books on a broad spectrum of topics. Some will start with the letter A too. If you're feeling particularly hungry, you may read about apples, appetizers, or ... ewww ... even anchovies!
The Big Book of Appetizers (Meredith Deeds and Carla Snyder)
Olives, Anchovies, and Capers (Georgeanne Brennan and Leigh Beisch)
So what tickles your fancy? Interested in Astrology? Read anything by Asimov? Or are you already checking out some appetizer recipes?