Discovery of five very low mass close binaries, resolved in the visible with lucky imaging

We survey a sample of 32 M5–M8 stars with distance 1 were found, even though our survey is sensitive to Δm≤ 5 (well into the brown dwarf regime). The distribution of orbital radii is in broad agreement with previous results, with most systems at 1–5 au, but one detected binary is very wide at 46.8 ± 5.0 au. We also serendipitously imaged for the first time a companion to Ross 530, a metal-poor single-lined spectroscopic binary. We used the new Lucky Imaging system, LuckyCam, on the 2.5-m Nordic Optical Telescope to complete the 32 very low mass star Sloan Digital Sky Survey (SDSS) i′ and z′ survey in only 5 h of telescope time.