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We investigate the bursty star formation histories (SFHs) of dwarf galaxiesusing the distribution of log($L_{H\alpha}/L_{UV}$) of 185 local galaxies. Weexpand on the work of Weisz et al. 2012 to consider a wider range of SFHs andstellar metallicities, and show that there are large degeneracies in aperiodic, top-hat burst model. We argue that all galaxies of a given mass havesimilar SFHs and we can therefore include the $L_{H\alpha}$ distributions(subtracting the median trend with stellar mass, referred to as $\Delta\text{log}(L_{H\alpha})$) in our analyses. $\Delta \text{log}(L_{H\alpha})$traces the amplitude of the bursts, and log($L_{H\alpha}/L_{UV}$) is a functionof timescale, amplitude, and shape of the bursts. We examine the 2-dimensionaldistribution of these two indicators constrain the SFHs. We use exponentiallyrising/falling bursts to determine timescales ($e$-folding time, $\tau$). Wefind that galaxies below $10^{7.5}$ M$_{\odot}$ undergo large (amplitudes of$\sim 100$) and rapid ($\tau < 30$ Myr) bursts, while galaxies above $10^{8.5}$M$_{\odot}$ experience smaller (maximum amplitudes $\sim 10$), slower ($\tau\gtrsim 300$ Myr) bursts. We compare to the FIRE-2 hydrodynamical simulationsand find that the burst amplitudes agree with observations, but they are toorapid in more massive galaxies ($M_* > 10^8$ M$_{\odot}$). Finally, we confirmthat stochastic sampling of the stellar mass function can not reproduce theobserved distributions unless the standard assumptions of cluster and stellarmass functions are changed. With the next generation of telescopes,measurements of $L_{UV}$ and $L_{H\alpha}$ will become available for dwarfgalaxies at high-redshift, enabling similar analyses of galaxies in the earlyuniverse.

A Closer look at Bursty Star Formation with $L_{H\alpha}$ and $L_{UV}$ Distributions