<p>From the mysterious site <em><a href="http://astro.vaporia.com/start/bondiradius.html" rel="nofollow noreferrer">Vaporia</a></em>, which is a fantastic index for astrophysics terms (and other things I'm seeing now): </p>

<blockquote>
  <p>The Bondi radius is analogous to the <a href="http://astro.vaporia.com/start/hillradius.html" rel="nofollow noreferrer">Hill radius</a>, both giving an idea
  of how far from an object, a medium (gas, dust) is likely to be drawn
  in and accreted. The Bondi radius takes into account the (relative)
  speed of the object through the medium, and the medium's density and
  sound-speed. Accretion due to material falling within the Bondi radius
  is called Bondi accretion. </p>
</blockquote>

<p>Try to picture a heavy object, perhaps a planet, travelling through a gaseous or dusty medium. Now, some of the gas is eventually going to be the victim of accretion to the planet. The planet is going to pull gas/dust from the medium and the Bondi radius tells you how far from the planet gas/dust is likely to be accreted to the planet. </p>

<p>Hopefully this is more clear!</p>

CC BY-SA 4.0
2020-05-04T14:24:31.130Z
2020-05-04T14:24:31.130Z
sbjartmar
<p>Can anyone help me by defining what is exactly Bondi Radius? I have searched far and wide but the results are very complicated and so far I have only rough idea of it but I just cant explain it very well</p>

CC BY-SA 4.0
2020-04-23T19:41:28.447Z
You mean you can't find the formula $r_{\rm B} = GM/(v^2+c_s^2)$ or you are having a hard time interpreting it?
AtmosphericPrisonEscape
CC BY-SA 4.0
2020-04-24T02:34:47.097Z
@AtmosphericPrisonEscape probably "so far I have only rough idea of it but I just cant explain it very well" makes it pretty clear
uhoh
CC BY-SA 4.0
2020-04-24T08:51:32.733Z
@uhoh As per usual, it would be better if you would not speak for other people, but let OP voice their opinion instead.
AtmosphericPrisonEscape
<radius>
Simple definition of Bondi Radius
Agustine Budiayawan
# Simple definition of Bondi Radius

(Asked by: username_0 on 2020-04-23)

Can anyone help me by defining what is exactly Bondi Radius? I have searched far and wide but the results are very complicated and so far I have only rough idea of it but I just cant explain it very well

**Tags:** radius
> **Comments:**
> **username_1**: You mean you can't find the formula $r_{\rm B} = GM/(v^2+c_s^2)$ or you are having a hard time interpreting it?  
> **username_2**: @AtmosphericPrisonEscape probably "so far I have only rough idea of it but I just cant explain it very well" makes it pretty clear  
> **username_1**: @uhoh As per usual, it would be better if you would not speak for other people, but let OP voice their opinion instead.  

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## 1 answers

### Answer by username_3 on 2020-05-04. Score: 1

From the mysterious site *[Vaporia](http://astro.vaporia.com/start/bondiradius.html)*, which is a fantastic index for astrophysics terms (and other things I'm seeing now):

> The Bondi radius is analogous to the [Hill radius](http://astro.vaporia.com/start/hillradius.html), both giving an idea
> of how far from an object, a medium (gas, dust) is likely to be drawn
> in and accreted. The Bondi radius takes into account the (relative)
> speed of the object through the medium, and the medium's density and
> sound-speed. Accretion due to material falling within the Bondi radius
> is called Bondi accretion.

Try to picture a heavy object, perhaps a planet, travelling through a gaseous or dusty medium. Now, some of the gas is eventually going to be the victim of accretion to the planet. The planet is going to pull gas/dust from the medium and the Bondi radius tells you how far from the planet gas/dust is likely to be accreted to the planet.

Hopefully this is more clear!


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