:::This is a matter of perspective, since arguably 'solar' (vis-à–vis stellar) is quite specific in and of itself.  Even though 'solar' has entered into informal usage somewhat when pertaining to systems around other stars (e.g., extrasolar), dictionaries always prescribe the specific usage.  Look up 'solar' itself in a dictionary and you'll note that there's no indication that it applies to other stars.  And, again, there is little reason to capitalise a common term and the Wp entry when other common, reputable publications do not.