<p>The standard reference, although it is getting a bit old, is (<a href="https://arxiv.org/abs/astro-ph/9701131" rel="nofollow noreferrer">Adams &amp; Laughlin 1997</a>).</p>
<p>The main issue is that these objects either get absorbed by central black holes, or escape galaxies and then presumably evaporate due to proton decay. When this happens depends on particle physics issues. Their lifetime becomes proportional to their mass.</p>

CC BY-SA 4.0
2024-01-10T15:18:29.100Z
When you say proportional to mass, are you saying that t~M (first power of mass)???
riemannium
CC BY-SA 4.0
2024-01-10T15:28:28.637Z
Yes. The decay rate makes the mass scale as $M_0 exp(-t/\tau)$ so whatever threshold endpoint mass you use the time until it is reached is $\propto M_0 \tau$.
Anders Sandberg
CC BY-SA 4.0
2024-01-09T13:50:55.277Z
2024-01-09T13:50:55.277Z
Anders Sandberg
<p>Stars have a lifespan scaling as <span class="math-container">$1/M^{2.5}_\star$</span> for sunlike stars or more generally <span class="math-container">$t\sim 1/M^3$</span> for general stars (more or less), black holes have a lifespan (according to simple Hawking evaporation scenarios) of <span class="math-container">$t\sim M^3$</span>. What we know about the lifetime span of neutron stars and black dwarfs? How do they (the time of life of those degenerate stellar systems) scale with mass? References would be welcome too!</p>

CC BY-SA 4.0
2024-01-07T23:37:35.610Z
An answer would require knowledge of proton decay or some other unknown mechanism. As far as we know, they are eternal.
John Doty
<star><neutron-star>
Lifespan of neutron stars and black dwarfs in terms of mass in years
riemannium
# Lifespan of neutron stars and black dwarfs in terms of mass in years

(Asked by: username_0 on 2024-01-07)

Stars have a lifespan scaling as $1/M^{2.5}\_\star$ for sunlike stars or more generally $t\sim 1/M^3$ for general stars (more or less), black holes have a lifespan (according to simple Hawking evaporation scenarios) of $t\sim M^3$. What we know about the lifetime span of neutron stars and black dwarfs? How do they (the time of life of those degenerate stellar systems) scale with mass? References would be welcome too!

**Tags:** star, neutron-star
> **Comments:**
> **username_1**: An answer would require knowledge of proton decay or some other unknown mechanism. As far as we know, they are eternal.  

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## 1 answers

### Answer by username_2 on 2024-01-09. Score: 1

The standard reference, although it is getting a bit old, is ([Adams & Laughlin 1997](https://arxiv.org/abs/astro-ph/9701131)).

The main issue is that these objects either get absorbed by central black holes, or escape galaxies and then presumably evaporate due to proton decay. When this happens depends on particle physics issues. Their lifetime becomes proportional to their mass.

> **Comments:**
> **username_0**: When you say proportional to mass, are you saying that t~M (first power of mass)???  
> **username_2**: Yes. The decay rate makes the mass scale as $M_0 exp(-t/\tau)$ so whatever threshold endpoint mass you use the time until it is reached is $\propto M_0 \tau$.  

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