NOAO >   Observing Info >   Approved Programs >   2018A-0004

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Program Information for 2018A-0004


PI: Andrei Tokovinin, NOAO, atokovinin@ctio.noao.edu
Address: CTIO, Casilla 603 AURA, La Serena Chile

CoI: Brian Mason, US Naval Observatory
CoI: William I Hartkopf, US Naval Observatory

Title: Dynamics of resolved triple systems and ``fast'' binaries

Abstract: High angular resolution of speckle interferometry enabled the discovery of an unusual class of multiple systems with comparable separations between components, straddling the dynamical stability limit. Such multiples are distinguished by moderate period ratios 1:5 to 1:30, small orbital eccentricities, and approximate co-planarity, like the quadruple system HD 91962. This suggests a special formation mechanism, possibly involving dissipative evolution in a disk. We continue to monitor several resolved multiple systems with the goal of determining their inner and outer orbits, looking for mean motion resonances and studying orbit coplanarity. We also collect positional measurements of tight nearby binaries with orbital periods of a few years for determination of their orbits, serving various astrophysical programs, e.g. binaries with planets or disks and young binaries. Ground-based speckle coverage at SOAR combined with the {it Gaia} astrometry will measure accurate masses for a variety of interesting stars.

Program Type: Long Term/Galactic

Scheduled Nights:
Run 1 (2018A):  SOAR/HRCam -- 2n on Mar 07 2018, Mar 27 2018, May 26 2018
Run 1 (2018B):  SOAR/HRCam -- 2n on Sep 24 2018, Dec 22 2018


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2018A-0004

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