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Spectroscopic orbit of the ex-eclipsing binain the young open cluster NGC 7209ry SS Lac

Lina Tomasella·Ulisse Munari
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Abstract

The no-longer-eclipsing system SS Lac in the young open cluster NGC 7209 has been recently announced to show a constant radial velocity. Puzzled by this finding, we have monitored the system during 1997 obtaining 24 Echelle+CCD spectra over 8 orbital revolutions. Our spectra reveal a nice orbital motion with periodic splitting and merging of spectral lines from both components. An accurate orbit has been derived, together with individual masses of the stars. SS Lac presents a moderately eccentric orbit and a probably full synchronization between stellar rotation and orbital revolution.

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Lina Tomasella, Ulisse Munari. 1998-05-04. Spectroscopic orbit of the ex-eclipsing binain the young open cluster NGC 7209ry SS Lac. https://arxiv.org/abs/astro-ph/9805019

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