R☉

Translingual Alternative forms The R is not always italic. Etymology R (radius) and subindex ☉ (sun). Symbol mul symbol R☉{{#if:{{DISPLAYTITLE:R☉}}}} mul astronomy solar radius: a unit of distance, equal to the radius of the Sun: 7×108 m or 110 R🜨. The inner edge of the [circumbinary] disc is at 317 R☉, well outside the inner binary orbit. mul sum of parts 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.