Astronomy app on iPhone 11

Astronomy is not quite an app, so it cannot be deleted. It is part of the Wallpaper setup, where you can choose to see your location on the globe, and use it as wallpaper on the Lock Screen. For the function to work, it requires access to your location.

If you don't want to use Astronomy wallpaper, you can disable its access to your location here:

Settings → Privacy & Security → Locations Services → Astronomy → Never

If you cannot see Astronomy in the list in Location Services, then it is because you have not used that wallpaper, and therefore not given it access to your location. So Astronomy does not have access to your location.

When you disable Astronomy in Cellular Data, Astronomy will not have access to send/receive data when you are using Cellular Data, but still on Wi-Fi. But since you haven't used Astronomy, it won't use data regardless. Nor your location.

Conclusion based on what you have told:

Astronomy app does NOT have access to your location or cellular. You can forget it and pretend it never existed.

You're welcome.