<p>See <a href="https://en.wikipedia.org/wiki/Hawking_radiation" rel="nofollow noreferrer">Hawking radiation</a>. The temperature of a black hole depends on its mass, and is given by: </p>

<p><span class="math-container">$T=\frac{hc^3}{16\pi^2GMk_B}$</span></p>

<p>Where <span class="math-container">$h$</span> is the Planck constant, <span class="math-container">$c$</span> is the speed of light, <span class="math-container">$G$</span> is Newton's gravitational constant, <span class="math-container">$M$</span> is the mass of the black hole, and <span class="math-container">$k_B$</span> is the Boltzmann constant.</p>

CC BY-SA 4.0
2019-12-05T05:40:06.617Z
There's a nice [Hawking radiation calculator](https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator)
PM 2Ring
CC BY-SA 4.0
2019-12-04T20:25:25.483Z
2019-12-05T05:38:59.467Z
2019-12-05T05:38:59.467Z
Allure
<p>If you are talking about the temperature of the event horizon, then it depends on the mass. Super-massive black holes have a temperature of <span class="math-container">$1.4 \times 10^{-14}$</span> Kelvin while a solar mass black hole has a temperature of only <span class="math-container">$6.0 \times 10^{-8}$</span> Kelvin. This temperature comes from the proposed Hawking radiation of black holes<span class="math-container">$^1$</span>. The reference below gives some temperatures for very small black holes.</p>

<ol>
<li><a href="https://phys.org/news/2016-09-cold-black-holes.html" rel="nofollow noreferrer">https://phys.org/news/2016-09-cold-black-holes.html</a></li>
</ol>

CC BY-SA 4.0
2019-12-04T20:29:46.893Z
2019-12-05T04:08:59.643Z
2019-12-05T04:08:59.643Z
Natsfan
<p>Are black holes hot or cold? I was thinking because I wanted to know if there any human sustainable temperature so we can travel in it.</p>

CC BY-SA 4.0
2019-12-04T19:27:40.213Z
Forget about traveling there. There's no solid surface to stand on, not to mention that doing so would turn you into a puddle of neutrons anyways.
John Dvorak
CC BY-SA 4.0
2019-12-04T19:29:48.930Z
What kind of energy is present in there?
Shaun
<black-hole>
What is the temperature of the black hole?
Shaun
# What is the temperature of the black hole?

(Asked by: username_0 on 2019-12-04)

Are black holes hot or cold? I was thinking because I wanted to know if there any human sustainable temperature so we can travel in it.

**Tags:** black-hole

> **Comments:**
> **username_1**: Forget about traveling there. There's no solid surface to stand on, not to mention that doing so would turn you into a puddle of neutrons anyways.  
> **username_0**: What kind of energy is present in there?  

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## 2 answers

### Answer by username_2 on 2019-12-04. Score: 3

See [Hawking radiation](https://en.wikipedia.org/wiki/Hawking_radiation). The temperature of a black hole depends on its mass, and is given by:

$T=\frac{hc^3}{16\pi^2GMk\_B}$

Where $h$ is the Planck constant, $c$ is the speed of light, $G$ is Newton's gravitational constant, $M$ is the mass of the black hole, and $k\_B$ is the Boltzmann constant.

> **Comments:**
> **username_3**: There's a nice [Hawking radiation calculator](https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator)  

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### Answer by username_4 on 2019-12-04. Score: 2

If you are talking about the temperature of the event horizon, then it depends on the mass. Super-massive black holes have a temperature of $1.4 \times 10^{-14}$ Kelvin while a solar mass black hole has a temperature of only $6.0 \times 10^{-8}$ Kelvin. This temperature comes from the proposed Hawking radiation of black holes$^1$. The reference below gives some temperatures for very small black holes.

1. <https://phys.org/news/2016-09-cold-black-holes.html>


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