R☉

Alternative forms

 * The R is not always italic.

Etymology

 * R (radius) and subindex ☉ (sun).

Symbol

 * 1)  solar radius: a unit of distance, equal to the radius of the Sun: 7&times;108 m or 110 R🜨.
 * The inner edge of the [circumbinary] disc is at 317 R☉, well outside the inner binary orbit.
 * 1)  The radius of the Sun specifically

Usage notes

 * R☉ may be distinguished from r☉, the latter not a unit of measurement but meaning radial distance from the sun (heliocentric distance). Unlike the unit R☉, r☉ is used specifically for our sun; for another star, r＊ or r✶ is likely to be used.