<p>Long and short GRBs are thought to arise from different types of event, involving different types of star. Therefore the question you should be asking is why are their event rates so similar?!</p>
<p>Long duration bursts are thought to be produced in the death throes of rapidly, rotating massive stars - the <a href="https://en.m.wikipedia.org/wiki/Hypernova" rel="noreferrer">hypernova</a> model. Short GRBs are thought to be produced during <a href="https://en.m.wikipedia.org/wiki/Kilonova" rel="noreferrer">kilonova</a> explosions, after the merger of two orbiting binary neutron stars. Short GRBs are less luminous than long GRBs, but they are also systematically closer, and so their observed gamma ray fluxes and hence detectability are similar.</p>
<p>However, these are quite different things, so there is no reason that they should share similar event rates.</p>

CC BY-SA 4.0
2020-08-17T09:02:21.567Z
I think a there little bit misunderstanding, Because my questions is that, Why the number of Long GRBs events occurrence is larger than Short GRBs events occurrence since on that plot the area covered by the long durations GRBs is greater than the short-duration GRBs.
sd_Dhara.45
CC BY-SA 4.0
2020-08-12T07:26:12.740Z
2020-08-12T07:33:17.740Z
2020-08-12T07:33:17.740Z
ProfRob
<p>I collected  <a href="https://gammaray.nsstc.nasa.gov/batse/grb/duration/" rel="nofollow noreferrer">from NASA</a> this histogram plotting the number of GRBs vs the duration of GRBs.
<a href="https://i.sstatic.net/mKzWp.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mKzWp.jpg" alt="histogram plotting no. of GRBs vs the duration of GRBs." /></a></p>
<p>Now my question is, why is the number of Long Gamma Ray Bursts (LGRBs) events occurrences greater than the number of Short Gamma Ray Bursts (SGRBs) event occurences, since on that plot the area covered by the long duration GRBs is greater than short duration GRBs?</p>

CC BY-SA 4.0
2020-08-17T09:37:05.863Z
You edit makes no sense. You are asking why is the number of long GRBs more than the number of short GRBs, because the graph shows that the number of long GRBs is more than the number of short GRBs??? Maybe it's a language problem?  Your existing question made sense. This does not. I regard it is unfair to completely change the nature of a question significantly after it has been answered and upvoted many times. If you have a different question then ask a different question.
ProfRob
<astrophysics><gamma-ray-bursts><high-energy-astrophysics><gamma-rays>
Why is the number of Long Gamma Ray Burst (LGRB) event occurrences greater than the number of Short Gamma Ray Burst (SGRB) event occurrences?
sd_Dhara.45
# Why is the number of Long Gamma Ray Burst (LGRB) event occurrences greater than the number of Short Gamma Ray Burst (SGRB) event occurrences?

(Asked by: username_0 on 2020-08-12)

I collected [from NASA](https://gammaray.nsstc.nasa.gov/batse/grb/duration/) this histogram plotting the number of GRBs vs the duration of GRBs.
[![histogram plotting no. of GRBs vs the duration of GRBs.](https://i.sstatic.net/mKzWp.jpg)](https://i.sstatic.net/mKzWp.jpg)

Now my question is, why is the number of Long Gamma Ray Bursts (LGRBs) events occurrences greater than the number of Short Gamma Ray Bursts (SGRBs) event occurences, since on that plot the area covered by the long duration GRBs is greater than short duration GRBs?

**Tags:** astrophysics, gamma-ray-bursts, high-energy-astrophysics, gamma-rays

> **Comments:**
> **username_1**: You edit makes no sense. You are asking why is the number of long GRBs more than the number of short GRBs, because the graph shows that the number of long GRBs is more than the number of short GRBs??? Maybe it's a language problem?  Your existing question made sense. This does not. I regard it is unfair to completely change the nature of a question significantly after it has been answered and upvoted many times. If you have a different question then ask a different question.  

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## 1 answers

### Answer by username_1 on 2020-08-12. Score: 8

Long and short GRBs are thought to arise from different types of event, involving different types of star. Therefore the question you should be asking is why are their event rates so similar?!

Long duration bursts are thought to be produced in the death throes of rapidly, rotating massive stars - the [hypernova](https://en.m.wikipedia.org/wiki/Hypernova) model. Short GRBs are thought to be produced during [kilonova](https://en.m.wikipedia.org/wiki/Kilonova) explosions, after the merger of two orbiting binary neutron stars. Short GRBs are less luminous than long GRBs, but they are also systematically closer, and so their observed gamma ray fluxes and hence detectability are similar.

However, these are quite different things, so there is no reason that they should share similar event rates.

> **Comments:**
> **username_0**: I think a there little bit misunderstanding, Because my questions is that, Why the number of Long GRBs events occurrence is larger than Short GRBs events occurrence since on that plot the area covered by the long durations GRBs is greater than the short-duration GRBs.  

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