Radial velocity monitoring of possible close red giant binary systems

Conference item

MACHO observations show that approximately 25% of semi-regular red variables in the LMC have a secondary period similar to10 times longer than the primary period of pulsation, which is usually the first overtone pulsation mode in these stars. Wood et al. (1999) have suggested that the long secondary periods (LSPs) may be due to the presence of a binary companion and associated dust cloud whose orbital period matches that of the LSP. In this poster, preliminary results of an investigation aimed at detecting the radial velocity variations associated with the proposed orbital motions are reported. There is tentative evidence that the red giants with LSPs do show velocity variations consistent with the presence of a companion and that a trailing, accreted dust cloud occupies approximately one quarter of the orbital plane.

Authors: Wood, P; Axelrod, T; Welch, D

• Publication status: Published
• Journal: EVOLUTION OF BINARY AND MULTIPLE STAR SYSTEMS
• Volume: 229
• Pages: 233-236
• Publication date: 2001-01-01
• Event title: Conference on Evolution of Binary and Multiple Star Systems
• ISBN: 1583810617