  We present new Hubble Space Telescope observations of three a priori known
starlight-scattering circumstellar debris systems (CDSs) viewed at intermediate
inclinations around nearby close-solar analog stars: HD 207129, HD 202628, and
HD 202917. Each of these CDSs possesses ring-like components that are
more-massive analogs of our solar system's Edgeworth- Kuiper belt. These
systems were chosen for follow-up observations to provide higher-fidelity and
better sensitivity imaging for the sparse sample of solar-analog CDSs that
range over two decades in systemic ages with HD 202628 and HD 202917 (both ~
2.3 Gyr) currently the oldest CDSs imaged in visible or near-IR light. These
deep (10 - 14 ksec) observations, with six-roll point-spread-function template
subtracted visible-light coronagraphy using the Space Telescope Imaging
Spectrograph, were designed to better reveal their angularly large, diffuse/low
surface brightness, debris rings, and for all targets probe their exo-ring
environments for starlight-scattering materials that present observational
challenges for current ground-based facilities and instruments.
Contemporaneously also observing with a narrower occulter position, these
observations additionally probe the CDS endo-ring environments seen to be
relatively devoid of scatterers. We discuss the morphological, geometrical, and
photometric properties of these CDSs also in the context of other FGK-star
hosted CDSs we have previously imaged as a homogeneously observed ensemble.
From this combined sample we report a general decay in quiescent disk
F_disk/F_star optical brightness ~ t^-0.8, similar to what is seen in at
thermal IR wavelengths, and CDSs with a significant diversity in scattering
phase asymmetries, and spatial distributions of their starlight-scattering
grains.

Solar and Stellar Astrophysics