A radial tree diagram visualizes hierarchical data from a CSV file, positioning the sun at the center with planets and moons radiating outward as labeled circles. The visualization uses a D3 v4 layout with `d3.stratify` to build the hierarchy and `d3.tree` for radial positioning, rendering SVG paths for links and nodes. Node labels rotate tangentially around the tree, while an internal/leaf distinction colors parent nodes differently. Data loads from `flare.csv` via `d3.csv`, and the custom `radialPoint` function converts polar coordinates to Cartesian for node placement.