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

TL;DR

This paper reports near-infrared observations of U Sco's 2010 outburst, revealing high-velocity ejected material and estimating the ejected mass, contributing valuable data for understanding recurrent nova eruptions.

Contribution

It provides early near-IR spectra and photometry of U Sco's outburst, highlighting unexpectedly high ejection velocities and estimating the ejected mass, expanding knowledge of nova eruption dynamics.

Findings

Detection of broad spectral line wings up to ~10000 km/s

Estimated upper limit of ejected mass as 10^-4.64 Msun

Early near-IR spectra reveal high-velocity ejecta

Abstract

We present near-IR observations of the 2010 outburst of U Sco. JHK photometry is presented on ten consecutive days starting from 0.59 days after outburst. Such photometry can gainfully be integrated into a larger database of other multi-wavelength data which aim to comprehensively study the evolution of U Sco. Early near-IR spectra, starting from 0.56 days 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 ~10000km/s 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]Msun for the ejected mass.