Final answer:
Astronomers tend to believe in concepts like dark matter due to strong indirect evidence, while UFOs lack reliable evidence and contradict our understanding of physics. The uninhabitability of the Sun is understood through knowledge of its extreme conditions and processes. The discovery of a wide variety of exoplanets has reshaped our models of planetary system formation.
Step-by-step explanation:
When deciding which astronomer's discoveries to believe, it's important to consider the evidence supporting their claims. The acceptance of dark matter among astronomers is because of various lines of indirect evidence, such as the rotation curves of galaxies, gravitational lensing, and the cosmic microwave background radiation. These observations are consistent with the existence of dark matter, even though it has not been directly observed.
In contrast, UFO sightings often lack reliable evidence and are not consistent with our understanding of physics and interstellar distances. William Herschel's hypothesis about the Sun being cool and inhabited can be modernly refuted with our understanding of the Sun's extreme temperatures and nuclear fusion processes, which make it uninhabitable. The discovery of exoplanets has challenged traditional models of planetary system formation, particularly due to the unexpected diversity of exoplanets and the existence of hot Jupiters.
Scientific consensus is built on extensive research, peer review, and empirical evidence, which is why certain astronomical ideas are more believable. Personal beliefs or anecdotes, like UFO sighting reports, typically do not meet the rigorous standards of scientific evidence.