The phrase "solar radius" refers to the distance from the center of the Sun to its outer edge, measured in terms of the radius (size) of the Sun. It helps scientists understand the size and scale of the Sun. Full definition
A sun - size star approaching within 30 solar radii of the monster, they calculate, would be ripped apart by the black hole's gravitational pull, which would be far stronger on the near side of the star than on the far side. (discovermagazine.com)
The gas giant is so big that it pulls the center of mass between it and the sun, also known as the barycenter, some 1.07 solar radii from the star's center — which is about 30,000 miles above the sun's surface. (businessinsider.com)
One will take a picture of the entire corona in infrared wavelengths out to 10 solar radii away from the sun's surface. (sciencenews.org)