An astronomy paradox? Nemesis or Tycho?

True scientists don't "believe" in hypothetical objects like Tyche and Nemesis, they may postulate their existence, that's all. There is no strong or conclusive evidence to support either body at present, just hints that may mean nothing. If Nemesis is a red dwarf, it is probably already in star catalogs, but it's orbit around the sun would not be apparent. There are probably many dwarf planet-sized bodies and upwards orbiting far out in the solar system, but their presence has little practical effect on the Earth.