your problem is that star and planet enties differ at various parameters.
the easier way is to use a the volcanic planet entity (copy and rename it as you like)
and just change the meshinfo part for the appearance.
you just need to copy the meshname from your star enitity and adjust these parameter:
typeNameStringID,hudIcon,smallHudIcon,infoCardIcon,mainViewIcon,undetectedMainViewIcon,picture
here an example like i made it with my companion stars:
meshInfo
typeNameStringID "IDSGalaxyScenarioTypeStarBlueCompanion"
asteroidTemplate "Empty"
dustCloudTemplate "Empty"
meshName "Star_Companion_Blue"
cloudColor ffffffff
nullMeshRadius 0.000000
nullMeshParticleEffect ""
hudIcon "HUDICON_STAR_BLUE"
smallHudIcon "HUDICONSMALL_STAR_BLUE"
infoCardIcon "INFOCARDICON_STAR_BLUE"
mainViewIcon "MAINVIEWICON_CSTAR_BLUE"
undetectedMainViewIcon "MAINVIEWICON_CSTAR_BLUE"
picture "STARPICTURE_BLUE"