ATRONOMY – COMOLOGY (42) CALCULATOR
Galactic Redshift
A precise tool.
What is the Galactic Redshift & How does it work?
Redshift (denoted (z)) measures how much the wavelength of light from a distant galaxy has been stretched by the expansion of the Universe. A larger redshift means the galaxy is farther away and its light has travelled longer through expanding space. In the low‑redshift regime the recession velocity of a galaxy can be approximated by the simple linear relation (v = z times c), where (c) is the speed of light. This is the first‑order expression of Hubble’s law before relativistic corrections become important. The calculator below lets you convert an observed redshift into a recession velocity, giving a quick sense of how fast a galaxy is moving away from us in the cosmic flow.
v = z times c
v = recession velocity (km/s)
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Result
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Frequently Asked Questions
What is redshift in astronomy?
Redshift measures how much the wavelength of light from a distant galaxy has been stretched by the expansion of the Universe.
How does redshift relate to distance?
A larger redshift indicates that the galaxy is farther away and its light has traveled longer through expanding space.
What is the formula used in this calculator?
The formula used is v = z × c, where v is the recession velocity, z is the redshift, and c is the speed of light.
When would you use this calculator?
You would use this calculator to estimate the distance or speed of a galaxy based on its observed redshift.
What does Hubble’s law state?
Hubble’s law states that galaxies move away from us at a rate proportional to their distance, which is expressed as v = H₀ × d, where v is the recession velocity, H₀ is the Hubble constant, and d is the distance.
How does this calculator differ from using Hubble’s law?
This calculator uses a simplified linear relation (v = z × c) for low-redshift galaxies, while Hubble’s law (v = H₀ × d) relates velocity to distance directly.
What is the speed of light in this calculation?
The speed of light (c) used in this calculation is approximately 299,792 kilometers per second.
Results are for informational purposes only and do not constitute professional advice.