# I Calculating semi-major axis and minimum mass of an exoplanet

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1. Jun 6, 2016

### Mauro Montemayor

Hello guys,

I'm doing my physics coursework on kepler's third law and I'm finding the minimum mass and semi-major axis of a unknown planet. I have the following data:

Stellar mass Mstar = 1.31 ± 0.05 Msun

Orbital period P = 2.243752 ± 0.00005 days

Radial velocity semi-amplitude: V = 993.0 ± 3 m/s

Inclination i = 84.32º ± 0.67

We assume eccentricity e=0

Gravitational constant, G=6.67408 × 10-11 m3 kg-1 s-2

Jupiter mass: Mj=1,898 × 10^27 kg

From this I found that,
semi-major axis = 5.49042 x 10^9 m = 0.037 AU
Minimum mass = 1.46082 x 10^28 kg = 7.696 Mjupiter

The results are correct. However, I am not able to find the uncertainties of these two values. I would appreciate some help with this matter.

Thank you,

Mauro

2. Jun 7, 2016

### Buzz Bloom

Hi Mauro:

If you show the actual calculations that you used to derive semi-major axis and Minimum mass, I think that I can show you how to calculate the uncertainties.

Regards,
Buzz