SIMBAD references

2017MNRAS.471L...1S - Mon. Not. R. Astron. Soc., 471, L1-L5 (2017/October-2)

Evidence for orbital motion of CW Leonis from ground-based astrometry.

SOZZETTI A., SMART R.L., DRIMMEL R., GIACOBBE P. and LATTANZI M.G.

Abstract (from CDS):

Recent Atacama Large Millimeter/submillimeter Array (ALMA) observations indicate that CW Leo, the closest carbon-rich asymptotic giant branch star to Sun, might have a low-mass stellar companion. We present archival ground-based astrometric measurements of CW Leo obtained within the context of the Torino Parallax Program and with >6 yr (1995-2001) of time baseline. The residuals to a single-star solution show significant curvature, and they are strongly correlated with the well-known I-band photometric variations due to stellar pulsations. We describe successfully the astrometry of CW Leo with a variability-induced motion (VIM) + acceleration model. We obtain proper motion and parallax of the centre-of-mass of the binary, the former in fair agreement with recent estimates, the latter at the near end of the range of inferred distances based on indirect methods. The VIM + acceleration model results allow us to derive a companion mass in agreement with that inferred by ALMA, they point towards a somewhat longer period than implied by ALMA, but are not compatible with much longer period estimates. These data will constitute a fundamental contribution towards the full understanding of the orbital architecture of the system when combined with Gaia astrometry, providing an ∼25 yr time baseline.

Abstract Copyright: © 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society

Journal keyword(s): astrometry - stars: AGB and post-AGB - binaries: general - circumstellar matter - stars: individual: CW Leo - stars: late-type - stars: late-type

Simbad objects: 1

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2019.12.11-04:40:10

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