# mass of extra-solar-planet from M, v and V

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Rating
ID
sspickle.mass of extra-solar-planet from M, v and V
UUID
72c8ef13-7d67-11e5-9770-bc764e2038f2

The Mass of an Extra-Solar Planet calculator computes the mass of a planet based on the mass of the star (M) and the velocity of the star (V) and the velocity of the planet (v).

INSTRUCTIONS:  Choose the preferred units and enter the following:

• (M)  This is the mass of the star.
• (V)  This is the velocity of the star.
• (v)  This is the velocity of the planet.

Planetary Mass (m):  The calculator returns the mass of the planet in kilograms.  However, this can be automatically converted to other mass units including Earth_Masses via the pull-down menu.

#### The Math / Science

If you know the mass of a star, and the orbital speed of the star and the planet, you can compute the mass of the planet using the fact that the total momentum is zero in the center of mass frame. This formula computes the mass of the planet using the mass of the star, and the two known speeds.