  In this work, we analyze the observational properties of thin-shell
gravastars under two astrophysical frameworks, namely surrounded by
optically-thin accretion disks and orbited by hot-spots. We consider the
thin-shell gravastar model with two free parameters, the gravastar radius and
ratio of mass allocated at the thin-shell, and produce the corresponding
observables via the use of numerical backwards ray-tracing codes. Regarding the
observations of accretion disks, our results indicate that, due to the absence
of a strong gravitational redshift effect, smooth gravastar configurations
cannot reproduce shadow observations when internal emission is assumed. We thus
expect such models to be excluded as candidates for supermassive objects in
galactic cores. Nevertheless, thin-shell gravastars with a large portion of
their total mass allocated at the surface can produce such an effect and are
thus adequate candidates for black-hole mimickers. In the context of hot-spot
orbits, the astrometrical observational properties of ultra-compact gravastars
resemble closely those of other ultra-compact objects e.g. fluid stars and
bosonic stars. However, for low-compacticity configurations, the
time-integrated fluxes feature additional contributions in the form of a
high-intensity plunge through image. These qualitative differences in the
observational properties of gravastars in comparison with black-hole spacetimes
could potentially be discriminated by the next generation of interferometric
experiments in gravitational physics.
