---
abstract: |
    [We analyze a sample of bright short bursts from the BATSE 4B-catalog and find that many short bursts are highly variable ($ \delta t_{min}/T\ll 1 $, where $ \delta t_{min} $ is the shortest pulse duration and $ T $ is the burst duration). This indicates that it is unlikely that short bursts are produced by external shocks. We also analyze the available (first 1-2 seconds) high resolution (TTE) data of some of the long bursts. We find that variability on a 10ms time-scale is common in long bursts. This result shows that some long bursts are even more variable than it was thought before ($ \delta t_{min}/T\approx
    10^{-4}-10^{-3} $).]{}
author:
- |
    Ehud Nakar & Tsvi Piran\
    Racah Institute, Hebrew University, Jerusalem 91904, Israel
title: Temporal properties of short GRBs
---

gamma-rays: bursts

Introduction
============

The temporal features of GRBs are among the more interesting clues on their origin. The temporal features of long bursts ($
T_{90}>2sec $) were widely investigated (e.g. Norris 1995; Norris et al. 1996; Lee, Bloom & Scargle 1995; Beloborodov Stern & Svensson, 2000), while only a few works (Scargle, Norris & Bonnel 1997; Cline, Matthey & Otwinowski 1999) discuss the temporal 