<p>Although it's a little tricky to say what "bigger" means in this context, the answer is, in most senses, no.</p>

<p>A supernova puts out about ten to a hundred times as much energy in the form of light, and hundred or more times as much matter is ejected. (A core-collapse supernova undoubtedly puts out much more energy in the form of neutrinos as well.) What matter <em>is</em> ejected by a kilonova <em>does</em> go out faster (30-60,000 km/s, versus about 10,000 km/s for supernova ejecta).</p>

<p>On the other hand, a kilonova puts out much more energy in the form of gravitational waves, so they're bigger in that sense.</p>

CC BY-SA 3.0
2017-10-17T16:26:59.917Z
2017-10-18T14:05:34.917Z
2017-10-18T14:05:34.917Z
Peter Erwin
<p>My question is straight forward.  Is a <a href="https://en.wikipedia.org/wiki/Kilonova" rel="nofollow noreferrer">kilonova</a> bigger than a supernova?</p>

<p><strong>Update</strong></p>

<p>How does a kilonova differ from a nova in terms of...</p>

<ul>
<li>luminosity</li>
<li>duration</li>
<li>energy</li>
<li>volume of space occupied by the ejecta</li>
<li>speed of the ejecta</li>
<li>other metrics?</li>
</ul>

CC BY-SA 3.0
2017-10-18T00:22:22.347Z
How would you define "bigger"? More luminous? More energetic? Longer-lasting?
HDE 226868
CC BY-SA 3.0
2017-10-18T14:21:24.347Z
Thanks, HDE226868!  I think I get it.  Your comment, the answer PeterErwin provided, and the link uhoh provided have given me a picture of what kilonovas are like.  I refined the question for the sake of the site...  I left out supernovas and "hypernovas" (just learned about the latter today) though maybe that info could go here, too.  Or maybe this question is answered well enough already.
daveloyall
CC BY-SA 3.0
2017-10-18T16:40:46.807Z
Kilonova sounds a lot like supermoon; mostly journalistic in nature. If you take it literally, it means a thousand times as much of *something*, in this case "nova".
Wayfaring Stranger
CC BY-SA 3.0
2017-10-22T09:01:41.197Z
Wayfaring Stranger -- That is the original intended meaning: roughly 1000 times as much energy as a (classical) nova.
Peter Erwin
<supernova>
Is a kilonova bigger than a supernova?
daveloyall
# Is a kilonova bigger than a supernova?

(Asked by: username_0 on 2017-10-17)

My question is straight forward. Is a [kilonova](https://en.wikipedia.org/wiki/Kilonova) bigger than a supernova?

**Update**

How does a kilonova differ from a nova in terms of...

* luminosity
* duration
* energy
* volume of space occupied by the ejecta
* speed of the ejecta
* other metrics?

**Tags:** supernova

> **Comments:**
> **username_1**: How would you define "bigger"? More luminous? More energetic? Longer-lasting?  
> **username_0**: Thanks, username_1!  I think I get it.  Your comment, the answer username_3 provided, and the link uhoh provided have given me a picture of what kilonovas are like.  I refined the question for the sake of the site...  I left out supernovas and "hypernovas" (just learned about the latter today) though maybe that info could go here, too.  Or maybe this question is answered well enough already.  
> **username_2**: Kilonova sounds a lot like supermoon; mostly journalistic in nature. If you take it literally, it means a thousand times as much of *something*, in this case "nova".  
> **username_3**: username_2 username_2 -- That is the original intended meaning: roughly 1000 times as much energy as a (classical) nova.  

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## 1 answers

### Answer by username_3 on 2017-10-17. Score: 13 | Accepted answer

Although it's a little tricky to say what "bigger" means in this context, the answer is, in most senses, no.

A supernova puts out about ten to a hundred times as much energy in the form of light, and hundred or more times as much matter is ejected. (A core-collapse supernova undoubtedly puts out much more energy in the form of neutrinos as well.) What matter *is* ejected by a kilonova *does* go out faster (30-60,000 km/s, versus about 10,000 km/s for supernova ejecta).

On the other hand, a kilonova puts out much more energy in the form of gravitational waves, so they're bigger in that sense.


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