- ❪𝛿’❫ Astronomical Coordinates ○
- ❪𝛿❫ High-Energy Astrophysics Quantities ○
- ❪𝛿₂❫ Astronomical Units ○
- Absorbing Column Density (nH) ○◂
- Eddington Luminosity (L𝘌𝘥𝘥) ○◂
- Orbital Frequency ○◂
- Orbital Inclination (i) ○◂
- Orbital Period (P𝘰𝘳𝘣) ○◂
- Redshift (z) ○◂
- Source Distance (D) ○◂
- Source Mass (M) ○◂
- Spectral Index (α) ○◂
- Velocity Curve Half-Amplitude (K₂) ○◂