Kappa Fornaci, a triple radio-star
Abstract
Bright and nearby (22pc) solar-type dwarf Kappa Fornaci (HIP 11072) is a triple system. The close pair of M-type dwarfs Ba,Bb with a tentative period of 3.7 days moves around the main component A on a 26-year orbit. The mass of the "dark companion" Ba+Bb is comparable to the mass of A, causing large motion of the photo-center. The combined spectro-interferometric orbit of AB is derived and the relative photometry of the components A and B is given. A weak signature of Ba and Bb is detected in the high-resolution spectra by cross-correlation and by variable emission in the Bahlmer hydrogen lines. The activity of the M-dwarfs, manifested by a previously detected radio-flare, is likely maintained by synchronization with their tight orbit. We discuss the frequency of similar hidden triple systems, methods of their detection, and the implications for multiple-star statistics.
Keywords
Cite
@article{arxiv.1301.1352,
title = {Kappa Fornaci, a triple radio-star},
author = {Andrei Tokovinin},
journal= {arXiv preprint arXiv:1301.1352},
year = {2015}
}
Comments
Accepted by AJ. 7 pages, 5 figures, 5 tables