Distância comóvel (z baixo)

The low-redshift comoving distance calculator is used in cosmology to estimate distances to celestial objects with small redshift (z), typical of nearby galaxies. The formula D ≈ cz/H₀ is a simplified approximation that relates recession velocity (c*z) to the Hubble parameter (H₀ ≈ 70 km/s/Mpc). It applies to z << 1, where cosmic expansion is approximately linear.

Redshift z measures light stretching due to cosmic expansion. For low z, comoving distance (D) assumes recession velocity is proportional to distance, ignoring relativistic nonlinear effects. This method is practical for nearby galaxies like Andromeda but not for high-redshift objects (z > 0.1) where curvature corrections are needed.

This calculator is suitable for amateur astronomy or studies of local galaxies. For accuracy, ensure H₀ units match (70 km/s/Mpc gives D in megaparsecs). Example: If z=0.01 and H₀=70 km/s/Mpc, D ≈ (3×10⁵ km/s * 0.01 * 1 Mpc)/70 ≈ 42.86 Mpc. Cross-check with astronomical catalogs for validation.

Note that this approximation neglects dark energy and spatial curvature. For precise cosmological research, use more advanced models integrating the Friedmann equations. The c/H₀ term represents the Hubble distance scale in current cosmology.