         
         var massRange: (min: SolarMass, max: SolarMass) {
             switch self {
-            case .o:
+            case .O:
                 return (min: 16, max: 90)
-            case .b:
+            case .B:
                 return (min: 2.1, max: 16)
-            case .a:
+            case .A:
                 return (min: 1.4, max: 2.1)
-            case .f:
+            case .F:
                 return (min: 1.04, max: 1.4)
-            case .g:
+            case .G:
                 return (min: 0.8, max: 1.04)
-            case .k:
+            case .K:
                 return (min: 0.45, max: 0.8)
-            case .m:
+            case .M:
                 return (min: 0.08, max: 0.45)
             }
         }

     The classification of a star. Based primarily on [this wikipedia page](https://en.wikipedia.org/wiki/Stellar_classification#Harvard_spectral_classification).
     */
    public enum Classification: Int {
        case o
        case b
        case a
        case f
        case g
        case k
        case m
        
        var tempRange: (min: Kelvin, max: Kelvin) {
            switch self {
            case .o:
                return (min: 30000, max: 52000)
            case .b:
                return (min: 10000, max: 30000)
            case .a:
                return (min: 7500, max: 10000)
            case .f:
                return (min: 6000, max: 7500)
            case .g:
                return (min: 5200, max: 6000)
            case .k:
                return (min: 3700, max: 5200)
            case .m:
                return (min: 2400, max: 3700)
            }
        }

        
        var referenceColor: (hue: CGFloat, saturation: CGFloat) {
            switch self {
            case .O:
                return (hue: 0.639, saturation: 0.457)
            case .B:
                return (hue: 0.634, saturation: 0.398)
            case .A:
                return (hue: 0.628, saturation: 0.251)
            case .F:
                return (hue: 0.741, saturation: 0.035)
            case .G:
                return (hue: 0.089, saturation: 0.11)
            case .K:
                return (hue: 0.092, saturation: 0.35)
            case .M:
                return (hue: 0.086, saturation: 0.636)
            }
        }
