The survey for DUST In Nearby Galaxies with Spitzer ( DUSTiNGS ) has identified hundreds of candidate dust-producing Asymptotic Giant Branch ( AGB ) stars in several nearby metal-poor galaxies .
We have obtained multi-epoch follow-up observations for these candidates with the Spitzer Space Telescope and measured their infrared ( IR ) lightcurves .
This has allowed us to confirm their AGB nature and investigate pulsation behavior at very low metallicity .
We have obtained high-confidence pulsation periods for 88 sources in seven galaxies .
We have confirmed DUSTiNGS variable star candidates with a 20 % success rate , and determined the pulsation properties of 19 sources already identified as Thermally-Pulsing AGB ( TP-AGB ) stars .
We find that the AGB pulsation properties are similar in all galaxies surveyed here , with no discernible difference between the DUSTiNGS galaxies ( down to 1.4 % solar metallicity ; [ Fe/H ] = -1.85 ) and the far more metal-rich Magellanic Clouds ( up to 50 % solar metallicity ; [ Fe/H ] = -0.38 ) .
These results strengthen the link between dust production and pulsation in AGB stars and establish the IR Period-Luminosity ( P – L ) relation as a reliable tool ( \pm 4 % ) for determining distances to galaxies , regardless of metallicity .