DDO68-V1: an extremely metal-poor LBV in a void galaxy

The lowest metallicity massive stars in the Local Universe with Z\sim \left( {{Z}_\odot }/50-{{Z}_\odot }/30 \right) are the crucial objects to test the validity of assumptions in the modern models of very low-metallicity massive star evolution. These models, in turn, have major implications for our understanding of galaxy and massive star formation in the early epochs. DDO68-V1 in a void galaxy DDO68 is a unique extremely metal-poor massive star. Discovered by us in 2008 in the HII region Knot3 with Z={{Z}_\odot }/35\,\left[ 12+\log \left( \text{O/H} \right)\sim 7.14 \right], DDO68-V1 was identified as an LBV star. We present here the LBV lightcurve in V band, combining own new data and the last archive and/or literature data on the light of Knot3 over the 30 years. We find that during the years 2008-2011 the LBV have experienced a very rare event of `giant eruption' with V-band amplitude of 4.5 mag (V\sim {{24.5}^m}-{{20}^m}).