I was told that the following statement is inaccurate, but could somebody please help why exactly the sentence is wrong?

Hot stars are very massive, and therefore live for only a relatively short time.

Does the confusion lie in the existence of white dwarfs?

  • 3
    $\begingroup$ Hello Anna. It's not clear what you are asking. Hot stars are massive (and massive stars are hot). They do "live" for a relatively short time. Why do you think it is inaccurate? What is the context? In any such short sentence there are surely a number of simplifications. After all, the connection between "hotness". "mass" and "lifespan" is not explained, and it might be better to say "massive stars are hot and therefore..." However its not really very clear what this means, and so I'm asking for more details. $\endgroup$
    – James K
    Aug 29, 2021 at 13:35
  • $\begingroup$ youtube.com/watch?v=u4s48svdhRI had to share :) $\endgroup$ Aug 29, 2021 at 13:39
  • $\begingroup$ web.njit.edu/~gary/202/Lecture17.html gives a good summary. $\endgroup$
    – James K
    Aug 29, 2021 at 13:59
  • $\begingroup$ Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. $\endgroup$
    – Community Bot
    Aug 29, 2021 at 16:57
  • $\begingroup$ "I was told..." by whom? $\endgroup$
    – James K
    Aug 31, 2021 at 11:57

2 Answers 2


It could be misleading since not all hot stars are high mass. White dwarf stars are hot compared to most other types of stars; yet they are, by definition, less massive than the stars from which they evolved.

The logical implication is the other way around: high mass stars are hotter than lesser mass stars, and therefore have shorter lifespans than lesser mass stars.

  • $\begingroup$ Do these sentences avoid misunderstanding? "Hot stars, namely O, B, and possibly A stars, are characterised by an effective temperature greater than 10 000 K; thus, their colour is blue. They are also very luminous, massive, and therefore, short-lived, as the time that a star spends on the main sequence is inversely proportional to its mass. " $\endgroup$
    – Anna-Kat
    Aug 30, 2021 at 4:08
  • $\begingroup$ @Anna-Kat Seems okay! $\endgroup$ Nov 7, 2021 at 12:59

That placement of the word massive bothers me. I like to see cause-effect trains in explanations. Massive does not inherently mean short-lived. High temperature and high density both cause higher reaction rate, which in turn causes shorter life. However, high mass does tend to cause high density and high temperature. So I would write that sentence: "Their large mass has squeezed them to a high temperature, causing high luminosity and short lifetime. Similarly, it is known that the time...is inversely...."

  • $\begingroup$ Welcome to Astronomy Stack Exchange. Your answer seems very similar to the other one. Is there anything that makes yours different? $\endgroup$ Sep 13, 2021 at 13:37

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