English

New binaries in the epsilon Cha association

Solar and Stellar Astrophysics 2017-10-25 v1

Abstract

We present Adaptive Optics-aided speckle observations of 47 young stars in the ϵ\epsilon Cha association, made at the 4-m Southern Astrophysical Research Telescope in the II-band. We resolved 10 new binary pairs, 5 previously known binaries and two triple systems, also previously known. In the separation range between 4 and 300 AU, the 30 association members of spectral types G0 and later host 6 binary companions, leading to the raw companion frequency of 0.010±0.040.010\pm0.04 per decade of separation, comparable to the main sequence dwarfs in the field. On the other hand, all 5 massive association members of spectral types A and B have companions in this range. We discuss the newly resolved and known binaries in our sample. Observed motions in the triple system ϵ\epsilon Cha, composed of three similar B9V stars, can be described by tentative orbits with periods 13 and 900\sim 900 years, and a large mutual inclination.

Keywords

Cite

@article{arxiv.1709.05044,
  title  = {New binaries in the epsilon Cha association},
  author = {Cesar Briceno and Andrei Tokovinin},
  journal= {arXiv preprint arXiv:1709.05044},
  year   = {2017}
}

Comments

12 pages, 6 figures. Accepted for publication in The Astronomical Journal

R2 v1 2026-06-22T21:43:54.654Z