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I just wanted to take a minute to ask about something; will there ever be such a thing as stars orbiting like planets - say there was a huge star, like an O-class or something, and in it's system was an inferior brown, red or even orange dwarf
You mean for example a binary stellar system with such a huge mass ratio between the components that the barycenter keeps inside the more massive one? As if the other star orbited the primary like in the architecture of the solar system. Sure! it is possible.
That said, It's also true that those are very difficult to detect since massive stars tend to be also the most luminous stars and the companions light gets washed out in the images since we need larger contrast to find them. But sure there are objects like that.
The mass ratio, q, of a binary system, a.k.a. the mass of the secondary, m2,
divided by the mass of the primary component, m1,
has a close-to-flat frequency distribution. That means that in general you can find as many stars with q=0.1 (one star is 10 times more massive than the other) as with q=1.0 (both stars have similar mass). It's interesting because this distribution is not totally flat, and not only that but it depends on the mass of the primary how this distribution behaves.
Look at this graph (and click on it to read the scientific paper where I took it)
This is the distribution for different stellar masses (here they used stellar types as an indicator). In the x-axis you have q=m2
and in the y-axis you have the, let's say, probability of finding that kind of system. Binary systems containing a brown dwarf as primary component are represented by the green triangles, M-dwarfs are represented by purple/magenta stars, G-dwarfs (like our Sun) are represented as blue/cyan hexagons and A-dwarfs are represented by yellow circles. As you can see in general the distribution is flat; for example if you have a collection of 100 binary stars whith a G-dwarf (sun-like) star as the main component then, using the graph above, you should expect around 12 systems with q=0.15 (meaning the secondary is very low-mass) and around 10 or 11 systems to have q=0.95 (meaning both stars are very similar in mass, like Alpha Centauri A and B). That's what flat distribution means, you have all the diversity equally represented somehow. But if you take a closer look you see that the distributions are not totally flat (in fact this diagram makes that clear) and you can see that it differs as it was dependant on the primary's mass (or stellar type in this case). As you can see there are fewer brown dwarfs with much smaller-mass companions than there are brwon dwarfs with similar mass companions (an interesting result that has probably a lot to do with brown dwarfs not been stars in many aspects). For the rest of objects you have that in general the flat distribution is deviated to a lower q preference. This is great news for us. We want extremely low q for the barycenter to be inside the primary star (so that we can say that the architecture of the stellar system is like the one of a planetary system) and we have that lower q's are more probable. Not only that! We have that for more massive stars (at least until A-type stars) we have this behaviour enhanced so there should be a lot of high-mass low-mass binary systems in the galaxy.
By the way it would be awesome if someone could make a diagram like this but using data from SE universe. Search randomly for binaries and calculate their q values, then see if the proportions of some q's is greater than others for different stellar types. If not like this then SE could be made more accurate with the real distributions.
This is not the entire story at all by the way. To have the barycenter inside the primary you don't only need a low q value but also a small separation between the two; two binary systems with the same q value but one on which the components are 2 AU away and the other where the distance is 200 AU has it's barycenter displaced from the center of the primary differently. Take a look at this equation:
Here a is the semi-mayor axis of the system and r is the distance between the center of the primary and the barycenter of the system. We want r to be r<R, where R is the radius of the primary star, so that the barycenter lies inside the primary star and the system looks like a planetary system (in terms of orbital architecture). This means that want r to be small, and that means we should make a small or the denominator large, and to make the denominator large we neet to make q small. So yeah our binary is possible and we now know it's probable in terms of the distribtion of q (there are many low q values in binaries as the graph showed us), but we still need to know if the distribution of q depends on a (q varying as a function of a). Who knows, maybe close binaries tend to have q closer to 1 (a.k.a. the closer binaries have similar mass components) and you only find small q's for wide binaries. In this case planetary-like architecture of the system could be much more improbable than we are guessing here. I don't know if there's any research article about this (there has to be, but now I have to leave because I exhausted my free time for today).