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`V = z*C`

Enter a value for all fields

The **Galaxy Recession Velocity** calculator computes the velocity of a galaxy away from Earth based on the redshift and the speed of light.

**INSTRUCTIONS**: Enter the following:

- (
**z**) Redshift

**Recession Velocity (V)**: The calculator returns the velocity in kilometers per second. However, this can be automatically converted to compatible units via the pull-down menu.

Red Shift is used to compute the recession velocity of a galaxy. The formula for the recession velocity of a galaxy is:

`V = z*C`

where:

- V = recession velocity
- z = redshift
- C = Speed of Light

A source of light moving toward or away from an observer will have it's spectrum shifted toward the blue (moving toward) or to the red (moving away). This formula gives the magnitude of the wavelength shift given the speed of the source relative to the observer (for speeds well below the speed of light only!).

The formula for Redshift is:

**z = (λ _{v} - λ_{0}) / λ_{0}**

where:

- z = red shift
- λv = Observed Wavelength
- λ0 = Resting Wavelength

The **Astronomy Calculator Suite** includes functions that are useful for studying astronomy and include the following:

- Kepler's 3
^{rd}Law formula T² = (4π • R³)/(G • M) - Small Angle Formula
*Small Angle Formula**α = S / D* - Flux and Magnitude formulas
- Telescope formulas
- Mass formulas
**Mass from Luminosity****Mass from Acceleration and Radius****Mass from Speed and Separation****Mass of extra-solar planet from mass of star, radius of star orbit and radius of exoplanet orbit****Mass of extra-solar planet from mass and velocity of star and velocity of planet****Black Hole Mass Calculator****Black Hole Event Horizon Calculator**

- Relative Size Formulas
- Wavelength Formulas
- Other Formulas
**Distance from absolute and apparent magnitude****Radius from Speed and Period****Speed of Circular Motion****Hubble Time****Galaxy Recession Velocity****Luminosity from Mass****Hubble's Law****Exoplanet Calculator****Orbital Radial Acceleration****Distance to Barycenter****Sakuma-Hattori Equation****Astronomical Distance Calculator**provides the distance from the Earth to numerous astronomical bodies (e.g. Sun, Moon, planets, stars, Milky Way's Center and Edge, Andromeda Galaxy)**Astronomical Distance Travel Time Calculator**computes the time to travel to distant parts of space at different velocities.**3D Vector Calculator****Drake Equation Calculator****Seager Equation Calculator****Friedman Equation Calculator****Lagrange Points L1 and L2****Schwarzschild Radius****Hill Sphere Radius****Escape Velocity**

**Related Astro Calculators:**

- Ellipse Calculator
- 3D Vector Calculator:
- Exoplanet Calculator contains formulas for studying planets outside of our Solar System.
- Astronomical Distance Calculator provides the distance from the Earth to numerous astronomical bodies (e.g. Sun, Moon, planets, stars, Milky Way's Center and Edge, Andromeda Galaxy)
- Astronomical Distance Travel Time Calculator computes the time to travel to distant parts of space at different velocities.
- Radius of Perigee
- Radius of Apogee