On deformations of AdS$_3$ solutions, supersymmetry and $G$-structures

We construct new families of supersymmetric AdS$_3$ solutions in both massive and massless Type IIA supergravity via deformations to known backgrounds preserving $\mathcal{N} = (4,0)$ and $\mathcal{N} = (6,0)$ supersymmetry. These deformations are performed along internal isometries and lead to backgrounds with fully preserved or reduced supersymmetry. Using the formalism of $G$-structures, we systematically characterise the resulting geometries and track the evolution of their supersymmetric properties under the deformation. In particular, we identify transitions among SU(3), SU(2), and identity structures, and demonstrate the preservation of Killing spinors through explicit spinor bilinear constructions. Additionally, we investigate D-brane embeddings in the deformed geometries, uncovering stable and supersymmetric configurations supported by the new backgrounds. Our results offer new insights into the classification of AdS$_3$ flux vacua and provide a concrete framework for understanding their potential holographic duals.