The 2010 early outburst spectrum of the recurrent nova U Scorpii

TL;DR

This paper presents optical spectra of the recurrent nova U Sco during its 2010 outburst, revealing unique spectral features and suggesting specific mass transfer dynamics in the system.

Contribution

It provides the first detailed optical spectra of U Sco during early outburst, highlighting the absence of typical absorption systems and proposing a model for its mass transfer behavior.

Findings

Lack of low ionization transient heavy element absorption system.

Dominance of inner Lagrangian L1 mass transfer.

Absence of circumbinary gas reservoir.

Abstract

Aims. We present optical spectra of the fast recurrent nova U Sco during its recent outburst, obtained within 24 hr of maximum light. Methods. We use medium resolution (R~4000) spectra taken with the with the MagE spectrograph on the Magellan (Clay) 6.5m telescope of the Las Campanas Observatories. Results. The spectrum is notable for its lack of a low ionization transient heavy element absorption system that is visible in the large majority of novae near maximum light. We suggest that this may be due to the dominance of inner Lagrangian L1 mass transfer and the absence of a circumbinary gas reservoir in this object