↩ 🔵 🔵 🔵 ❪✺_ₛₛ❫ Astronomical Subsets ○ ❪✺_ₜₛ❫ Physical Typesets ○ ❪✺_ₜₛ❫ High-Energy Astrophysics Typesets ○ ❪𝛿’❫ Astronomical Coordinates ○ ❪𝛿’❫ Astronomical Dates ○ ❪𝛿’❫ Epochs ○ ❪𖣐₂’❫ Observatories ○