Brown dwarfs, which answer very well to the ‘jump points’, points of ‘dark’ mass which serve as spatial tethers, have been known to exist for some little while—sometimes when you predict something has to exist, and they find it, you can be so smug for at least a week—but they are discovering classes of these objects.

Curiously they are all the dimensions of Jupiter—regardless of mass. What sets them apart as classes is their temperature. The brightest, L class, do radiate, do have atomic process, and are 2600 Fahrenheit. The L Class are 1700 degrees. The dimmest, the Y class, do not emit, but reflect light like a planet, and they are also the coolest, at about 80 degrees. The fact that the L’s have a huge mass difference despite their size is really quite a thought problem. Why do they work out that way? Is our solar system going to lose another planet as they reclassify Jupiter?

It seems to me that matter, given a chance, will coalesce into lumps, and if enough lumps get together they become larger lumps, and if they get really big, they ignite and become stars. But that leaves a bunch that are too small, having absorbed everything they can, and possibly having an iron core (not good for stars) and that never will make it to star status, and have no anchoring star near enough to grab them and make their existence more exciting. It takes, imho, physics to make classes—in the sense that nature is full of gradations so many and so smooth in transition that they have to kick a physical law to distinguish themselves into a class, eg, reach the magical limit of mass and internal collapse from their own ‘weight’ that they start fusing atoms in their core, ie, ignite—at which point the pressure of their internal cookery inflates them somewhat, and they keep that star-size and their fusion until they flat run out of material and go catastrophic.

Brown dwarfs don’t have the mass. Ergo they just—sit—probably until the heat-death of the universe.