Questions from Disputed Facts Template

Hello, I've added the {{Factual accuracy}} template because of three items I think warrant some discussion:

• First, there is a dark green arrow connecting "Planetary Nebula" to "White Dwarf" stars. I may have missed something but isn't a white dwarf a remnant of a nova or super nova? And wouldn't the Planetary Nebula possibly lead to new stellar production?
• Although most stars are binary stars, this is not guaranteed. (A prime example is in our own back yard.) So the line from "Red Giant" to "Binary white dwarf" is a bit confusing. Not only that, the line from "Nova" (a stellar remnant I assume) also going to "Binary white dwarf" is also confusing. I seriously doubt they are created by a Red giant meeting a Nova out in space. I know binary systems can have their own evolution, but the way it is depicted here does not seem accurate.
• Third, there are no lines or images for red dwarf stars since they have their own evolution line. However, I do think they should be included since they are still part of the Main sequence and are more massive than the already-included Brown dwarf stars.
• Bonus: it would be nice to see how the different types of stellar remnants connect back to Molecular clouds to begin the cycle once again.
• Actually, although I can't read Hebrew, the lines in File:Stellar evolution Hebrew.png seem more accurate. Also, the numbers there are very different.
  • Ah, looking at Chandrasekhar limit (on the English wikipedia) that 1.4M seems to be the limit of the mass of the resulting star, not the original, collapsing star. The other number is from the Tolman–Oppenheimer–Volkoff limit.
  • It would be nice if both pairs of numbers (pre- and post-collapse masses) could be expressed unambiguously in this diagram.
  • That said, I don't know where the other two masses originate (8M and 40M for Neutron star and Black Hole, respectively) so I'll have to dig through articles to find that. It would be nice if the page description included all that information. (Which I can add once I find it.)
    • So far, the only reference I've found is Template:Star nav that links to Hertzsprung–Russell diagram but those talk about luminosity and color but not mass. The Main sequence, Subgiant and Giant star articles don't say anything about the 8M solar mass "cutoff" between "Low-mass star" and "Massive star" that's shown in this diagram.

Thanks, --Stux (talk) 14:21, 2 July 2025 (UTC)

I would also add that the arrows from Neutron Star to Pulsar and Black Hole to X-ray Emission are misleading:

• Pulsars are a subtype of neutron stars - one does not evolve into another, and not all neutron stars become pulsars
  • In explicit terms, a neutron star that becomes a pulsar does not cease being a neutron star, and pulsars can come into existence without first going through a non-pulsar neutron star phase
• Emission of X-rays is a feature that may occur with some black holes, but are not a necessary evolution of them
  • Furthermore, if a black hole emits X-rays, the black hole continues to exist; it does not "become" an X-ray emission
  • X-rays are one of many types of energy that may be emitted by a black hole
    • More accurately, the accretion disk surrounding a black hole is what emits energy, not the black hole itself
  • I wonder if the author may have misinterpreted Hawking radiation as some type of electromagnetic energy emission? The prevailing theory is that Hawking radiation will cause all black holes will eventually evaporate, though on a timescale of > 10⁶⁷ years, and not nearly energetic enough to be detected as an emission

157.131.180.27 00:07, 15 July 2025 (UTC)