2020/07/16 by T. Mazeh, Mazeh, Tsevi, S. Faigler +1
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astrophysical Phenomena and Observations #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2007.08522
openalex publication_date 2020/07/16 · openalex created_date 2022/07/24 · openalex updated_date 2026/07/28
A recent paper by Rivinius et al. proposed that HR 6819 is a triple system,\nwith a distant Be star and a binary of 40-day orbit, composed of a B3 III giant\nand a dormant black hole (BH). We suggest that the evidence for this model is\nnot conclusive. In an alternative model, the companion of the giant is by\nitself a short-period binary in, say, a \∼4-day orbit, consisting, for\nexample, of two A0 stars. Each of the two A0 stars should contribute\n
sim4 % of the total brightness of the system in the V band, and their\nspectral lines are moving due to their assumed orbital motion with an unknown\nperiod. Therefore, only a careful analysis of the observed spectra can exclude\nsuch a model. Before such an analysis is presented and upper limits for the\ndepths of the hypothetical A0 star absorption lines are derived, the model of a\nhidden close pair is more probable than the BH model.\n