IPA: /ˌæstrəˈfɪzɪkli/
KK: /æstrəˈfɪzɪkli/
In a way that relates to the branch of science that deals with the physical properties and phenomena of celestial bodies and the universe.
The stars are studied astrophysically to understand their formation and evolution.
Astrophysically → It is formed from "astro-" (from Greek "astron", meaning star) and "physical" (from Greek "physikos", meaning natural or pertaining to nature) with the suffix "-ly" (meaning in a manner). The word "astrophysically" refers to something that relates to the physical properties and phenomena of stars and celestial bodies.
Think of 'astro-' meaning 'star' and 'physical' relating to 'nature' — so astrophysically means relating to the natural properties of stars.