Einstein-scalar-Gauss-Bonnet theories lead to second order field equations, that feature a wide variety of interesting compact solutions.
Depending on the coupling function of the scalar field to the Gauss-Bonnet term, different types of solutions are obtained.
In this talk I will focus on coupling functions, that allow the black hole solutions of General Relativity to remain solutions of the field equations, but that yield in addition scalarized solutions. Besides a variety of scalarized black hole solutions I will discuss also other types of compact solutions.
These may feature light rings and echoes and quality as UCOs, ultra-compact objects.