<p>The speed of the blast front depends on the initial energy release and the density of the medium into which it is expanding, see <a href="http://www.astronomy.ohio-state.edu/~ryden/ast825/ch5-6.pdf">here</a>.</p>

<p>Theory suggests and <a href="http://jila.colorado.edu/~dick/Racusin09.pdf">measurements confirm expansion</a> rates of the order of thousands of km/s or a few $\times 10^6\ \mbox{m/s}$ or  $\sim 1\% \mbox{c}$.</p>

CC BY-SA 3.0
2015-07-22T10:32:43.087Z
The initial velocity of the blast wave is quite a bit larger, more like 10,000 to 30,000 km/s, i.e. ~10% of the speed of light. Still less than a quarter of the speed of light, though.
pela
CC BY-SA 3.0
2015-07-22T12:08:55.910Z
Crab nebula, remnant of SN 1054, is still expanding at  1,000 kilometers per second: http://apod.nasa.gov/apod/ap130905.html
Wayfaring Stranger
CC BY-SA 3.0
2015-07-22T04:10:39.327Z
2015-07-22T04:10:39.327Z
Conrad Turner
<p>How fast does the blast front of a supernova expand at? Is it close to the speed of light or is it less than a quarter of the speed of light?</p>

<supernova><explosion>
Speed of blast from supernova
LDC3
# Speed of blast from supernova

(Asked by: username_0 on 2015-07-22)

How fast does the blast front of a supernova expand at? Is it close to the speed of light or is it less than a quarter of the speed of light?

**Tags:** supernova, explosion

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## 1 answers

### Answer by username_1 on 2015-07-22. Score: 5 | Accepted answer

The speed of the blast front depends on the initial energy release and the density of the medium into which it is expanding, see [here](http://www.astronomy.ohio-state.edu/~ryden/ast825/ch5-6.pdf).

Theory suggests and [measurements confirm expansion](http://jila.colorado.edu/~dick/Racusin09.pdf) rates of the order of thousands of km/s or a few $\times 10^6\ \mbox{m/s}$ or $\sim 1\% \mbox{c}$.

> **Comments:**
> **username_2**: The initial velocity of the blast wave is quite a bit larger, more like 10,000 to 30,000 km/s, i.e. ~10% of the speed of light. Still less than a quarter of the speed of light, though.  
> **username_3**: Crab nebula, remnant of SN 1054, is still expanding at  1,000 kilometers per second: http://apod.nasa.gov/apod/ap130905.html  

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