# What is a stellar component?

I have a question where I have to calculate the orbital inclination of a planet, so that it isn't a exoplanet but a stellar component. The mass of the star it is orbiting is 1.1 $$M_☉$$. Does the exoplanet has a special mass if it is a stellar component (for example 0.5 $$M_☉$$) or is there another relation?

The question was made out of a few sub-questions. It is about 51 Peg b. In the first question, I had to calculate the half long ax (=0.05284 AU), the eccentricity (=0.013) and the $$mass*sin(i)$$ (=0.500 $$M_J$$) In the second question, I had to calculate the inclination at which the mass of the planet is 4 $$M_J$$ (=7.18°) and the inclination at which it wasn't a planet, but a stellar component.

• So you're asking what happens if instead of an exoplanet orbiting a star, it is another star that is orbiting? Orbital inclination relative to what? The line of sight? Mar 7, 2020 at 10:55
• Highly confused/confusing. Needs much clarification. Mar 7, 2020 at 11:19
• The Q seems to involve radial velocity based minimum mass and substellar objects. Mar 7, 2020 at 12:31
• @MikeG Yes, There is a radial velocity graph given. The graph is the same as in this site
– BOB
Mar 7, 2020 at 12:58
• There are a couple of potentially interesting questions in here: where the dividing line between stars and substellar objects is (as far as I can tell there isn't an existing question there), and whether the approximation that leads to writing the minimum mass as $m \sin i$ remains valid in that mass range. Which bit in particular are you interested in?
– user24157
Mar 7, 2020 at 13:39