Man pages matching name astro::fits::header::ast in section 3pm:

Astro::FITS::Header::AST.3pm.en	debian 10 / libastro-fits-header-perl
Astro::FITS::Header::AST.3pm.en	debian 11 / libastro-fits-header-perl
Astro::FITS::Header::AST.3pm.en	debian 12 / libastro-fits-header-perl