<p>Neutron stars are generally not compact enough to have an ergosphere. Typically, the radius of a neutron star is several times the Schwarzschild radius corresponding to its mass. The ergosphere however starts at the Schwarzschild radius.</p>

CC BY-SA 4.0
2020-11-29T10:15:06.343Z
Well, thank you @mmeent, i see.
Chen
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2020-11-29T14:27:52.513Z
In addition, one could say that any object compact enough to have an ergosphere automatically become a black hole.
jng224
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2020-11-29T15:30:21.490Z
@Jonas It is not so simple, since the horizon radius of a spinning black hole can be as small as half the Schwarzschild radius.
TimRias
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2020-11-29T09:51:17.940Z
2020-11-29T09:51:17.940Z
TimRias
<p>Ergospheres are a property of black holes, and do neutron stars have it? If yes, why seldom article mentions that; if no, why can't neutron stars have this ergosphere component?</p>

<black-hole><neutron-star>
Do neutron stars have an ergosphere?
Chen
# Do neutron stars have an ergosphere?

(Asked by: username_0 on 2020-11-29)

Ergospheres are a property of black holes, and do neutron stars have it? If yes, why seldom article mentions that; if no, why can't neutron stars have this ergosphere component?

**Tags:** black-hole, neutron-star


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## 1 answers

### Answer by username_1 on 2020-11-29. Score: 1 | Accepted answer

Neutron stars are generally not compact enough to have an ergosphere. Typically, the radius of a neutron star is several times the Schwarzschild radius corresponding to its mass. The ergosphere however starts at the Schwarzschild radius.

> **Comments:**
> **username_0**: Well, thank you @mmeent, i see.  
> **username_2**: In addition, one could say that any object compact enough to have an ergosphere automatically become a black hole.  
> **username_1**: @Jonas It is not so simple, since the horizon radius of a spinning black hole can be as small as half the Schwarzschild radius.  

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