Subdwarf B Binaries from the Edinburgh--Cape Survey

TL;DR

This study reports initial findings on the orbital characteristics of subdwarf B star binaries from the Edinburgh-Cape survey, highlighting the detection of several binary systems and preliminary orbital solutions.

Contribution

First orbital solutions for sdB binaries from the Edinburgh-Cape survey, with identification of new binary candidates and initial orbital parameter constraints.

Findings

15 out of 35 sdB stars are confirmed binaries.

Orbital parameters secured for 2 systems.

Some candidates show potential long-period binaries.

Abstract

We present the first results of a campaign to obtain orbital solutions of subdwarf B (sdB) stars from the Edinburgh-Cape survey. We have obtained blue spectra of 35 sdBs, 20 of which have been observed in more than two epochs. 15 out of the 35 are certain binaries with a few other objects showing radial velocity variations with small amplitude, possibly long period sdB binaries. We have secured the orbital parameters for 2 of the 15 systems and narrowed down the orbits of another one to a small range of periods. These preliminary results only use data taken up to December 2003.