Receding Source Redshifts the Line - Observational Astrophysics: Distance, Flux, Transits, and Spectra Step by Step

A positive signed speed gives a positive normalized line shift. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

The shift ratio is radial speed over light speed

The training light speed is 6 meters per second and the radial speed is 1 meter per second.

\frac{v}{c}=\frac{1\ \text{m}/\text{s}}{6\ \text{m}/\text{s}}

A positive signed ratio is a redshift training case

The checked shift ratio is 1/6. The lesson does not claim a real line profile.

\Delta\lambda/\lambda=\tfrac{1}{6}