Recessional Velocity Calculator

Formula

The formula to calculate the Recessional Velocity (Vr) is:

\[ Vr = H \times D + Vpec \]

Where:

\( Vr \) is the recessional velocity (MPH).
\( H \) is the Hubble constant (MPH/light year).
\( D \) is the proper distance (light years).
\( Vpec \) is the peculiar velocity (MPH).

What is Recessional Velocity?

Recessional velocity is the speed at which astronomical objects recede from an observer due to the expansion of the universe. It is calculated using the Hubble constant, the proper distance, and the peculiar velocity of the object.

Example Calculation

Consider an example where:

Hubble Constant (H): 342,000 MPH/light year
Proper Distance (D): 1,000,000 light years
Peculiar Velocity (Vpec): 10,000 MPH

Using the formula to calculate the Recessional Velocity:

\[ Vr = 342000 \times 1000000 + 10000 = 342000000000 + 10000 = 342000010000 \text{ MPH} \]

This means that the recessional velocity for this example is approximately 342,000,010,000 MPH.