Landing page for project GA043

Binary/multiple stellar systems are as abundant as single stars. They are very interesting cosmic laboratories as they are related to many astrophysical phenomena. In the case of AGB (and post-AGB) stars, binaries are the most likely explanation for the shaping of non spherical PNe, a long standing problem in stellar evolution. While many binaries are known in the PNe phase, there are few examples in the previous AGB phase. Hydrodynamical models of the binary interaction are available, but well known parameters for orbits are non-existent. We propose to observe two binaries with an AGB primary, Mira and R Aqr, at 7mm using the Global VLBI array in wide-band continuum and SiO masers. The strong SiO masers will be used to self-calibrate the observations and pinpoint the location of the AGB component. The continuum will be used to directly detect the WD companion (or companions in the case of Mira; very probably a triple system) or its close environments (non-thermal emission from accretion disks/jets). If successful, this proposal will open a new way to determine orbits in binaries at the AGB phase and better study their role in late stellar evolution and PNe shaping.

This data is part of the archive of VLBI data maintained by JIVE on behalf of the EVN, a network of radio telescopes located primarily in Europe and Asia, with additional antennas in South Africa. The EVN archive itself has the DOI https://doi.org/10.17616/R3Z197