  The lifetime $\tau$ of an isothermal and purely diffusively dissolving
droplet in a host liquid scales as $\tau \sim R_0^2$ with its initial radius
$R_0$ [Langmuir, Phys. Rev. 12, 368 (1919)]. For a droplet dissolving due to
natural convection driven by density differences, its lifetime scales as
$\tau\sim R_0^{5/4}$ [Dietrich et al., J. Fluid Mech. 794, 45 (2016)]. In this
paper we experimentally find and theoretically derive yet another droplet
dissolution behavior, resulting in $\tau \sim R_0^4$. It occurs when the
dissolution dynamics is controlled by local heating of the liquid, leading to a
modified solubility and a thermal Marangoni flow around the droplet. The
thermal gradient is achieved by plasmonic heating of a gold nanoparticle
decorated sample surface, on which a sessile water droplet immersed in
water-saturated 1-butanol solution is sitting. The resulting off-wall thermal
Marangoni flow and the temperature dependence of the solubility determine the
droplet dissolution rate, resulting in a shrinkage $R(t) \sim (\tau -t )^{1/4}$
of the droplet radius and thus in $\tau \sim R_0^{4}$.
