Landing page for project EO019

Lambda Andromedae is a spectroscopic binary system found at a distance of 25.9 pc consisting of a primary star (G8 IV) and a low-mass/sub-stellar companion. We are requesting 18 h of time on the EVN to observe at 5 GHz to resolve the opaque radio surface associated with the stellar wind of the primary star. These observations will enable estimates of the stellar mass-loss rate, spin-down times, and evolutionary state to be made, while also providing novel information on the topology and density of the optically thick boundary. Lambda And has been extensively observed at X-ray, EUV, optical and radio wavelengths and whilst the stellar wind has been detected from 4.5-8.3 GHz, it has never been spatially resolved. These observations will confirm (or otherwise invalidate) predictions of lambda And's stellar wind environment made by O Fionnagain et al. 2021, and form the basis for more nuanced modelling efforts to better understand the impact of stellar winds for evolving solar-mass stars.

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