Far Ultraviolet Spectroscopic Explorer Spectroscopy of the Nova-like BB Doradus

TL;DR

This paper analyzes FUSE spectra of the nova-like star BB Doradus, modeling its accretion disk and elemental abundances, and estimates its distance and accretion rate.

Contribution

It provides the first detailed spectral analysis of BB Doradus, revealing elemental over-abundances and constraining its physical parameters.

Findings

Accretion rate estimated at 1.E-9 Solar mass/year.

Over-abundance of silicon and sulfur by 3 and 20 times solar.

Distance estimated around 650 parsecs.

Abstract

We present an analysis of the Far Ultraviolet Spectroscopic Explorer ({\it{FUSE}}) spectra of the little-known southern nova-like BB Doradus. The spectrum was obtained as part of our Cycle 8 {\it FUSE} survey of high declination nova-like stars. The FUSE spectrum of BB Dor, observed in a high state, is modeled with an accretion disk with a very low inclination (possibly lower than 10deg). Assuming an average WD mass of 0.8 solar leads to a mass accretion rate of 1.E-9 Solar mass/year and a distance of the order of 650 pc, consistent with the extremely low galactic reddening in its direction. The spectrum presents some broad and deep silicon and sulfur absorption lines, indicating that these elements are over-abundant by 3 and 20 times solar, respectively.