5 ms·

Since they are watching the star wobble, they probably have exact inclinations.

• hinkley 9y ago
  Seems like it would have to be. If you've worked out from the wobble what the mass and orbit are it would stand to reason you've either calculated or at least stated an assumption regarding the inclination.
  • tadfisher 9y ago
    You can put a lower bound on both, but inclination introduces an unknown upper bound.
    • Zitrax 9y ago
      But shouldn't they have _some_ upper bound ? I guess for example that it's unlikely they are larger than 100 Earth masses since they call them Earth-sized.
• semaphoreP 9y ago
  Measuring the star wobble (i.e. doppler shift) doesn't give inclinations.
• goodcanadian 9y ago
  "Wobble" is perhaps a imprecise term. What is actually measured is the doppler shift of a spectral line in the star. In other words, you are measuring the velocity of the star in the radial direction (towards and away from the Earth). By measuring how the velocity changes over time, you can get a orbital period for the planet. By measuring the magnitude of the velocity change, you can get a lower bound on the mass of the planet. It is only a lower bound as depending on the orbital inclination, some of the movement will be in the perpendicular direction (back and forth on the sky). We are unable to measure this movement precisely enough to detect (in most cases).