DukeofNuke wrote: DEyncourt wrote: Astronomers find 7 Earth-sized planets in orbit around dwarf star:
Mind you: the colors for all of the planets in TRAPPIST-1 are just artist's renditions, AND the scale of their estimated sizes are based on the
probability that these are all mostly rocky planets like those pictured in our Solar System which are of similar masses.
0.011 AU ? A 36 hour
year? Jesus! If it's rock, it's liquid rock ...
TRAPPIST-1 is a
TINY dwarf star, just a bit more massive than that required for it to sustain fusion so somewhere not much above 80 Jupiter-masses (our current estimate of that limit). This dwarf star generates about 1/2000th the light that our Sun does. If we were to take the Earth and put in the TRAPPIST-1 system at Earth's orbit it likely would be so cold that all of the Earth's atmosphere would be frozen except for helium and hydrogen.
As it happens Jupiter is about as large in diameter as any
planet can be. Adding more mass to Jupiter would compress its gases more without increasing its diameter very much up to the point when fusion could be sustained at the core. When that happens a dwarf star will balloon out to a much larger size though still tiny compared to our Sun.
On the other hand: judging from the relatively few dwarf stars that we can see--because they are so small we cannot see many outside 50 light years from Earth much less study them to any degree--dwarf stars are subject to violent storms such that likely they will strip any small rocky planet like the Earth of any atmosphere.
STILL, this at least is an argument towards a relatively high prevalence of planets in star systems.
