Near-infrared studies of the 2010 outburst of the recurrent nova U Scorpii

We present near-infrared (near-IR) observations of the 2010 outburst of U Sco. JHK photometry is presented on 10 consecutive days starting from 0.59 d after outburst. Such photometry can gainfully be integrated into a larger data base of other multiwavelength data which aim to comprehensively study the evolution of U Sco. Early near-IR spectra, starting from 0.56 d after outburst, are presented and their general characteristics discussed. Early in the eruption, we see very broad wings in several spectral lines, with tails extending up to similar to 10 000 km s(-1) along the line of sight; it is unexpected to have a nova with ejection velocities equal to those usually thought to be exclusive to supernovae. From recombination analysis, we estimate an upper limit of 10(-4.64+0.92-0.74) M-circle dot for the ejected mass.