Added units for Astronomy.

Common/UnitDefinitions/Length.json

@@ -293,6 +293,50 @@
           "Abbreviations": [ "h", "hh" ]
         }
       ]
+    },
+    {
+      "SingularName": "AstronomicalUnit",
+      "PluralName": "AstronomicalUnits",
+      "FromUnitToBaseFunc": "x * 1.4959787070e11",
+      "FromBaseToUnitFunc": "x / 1.4959787070e11",
+      "XmlDocSummary": "One Astronomical Unit is the distance from the solar system Star, the sun, to planet Earth.",
+      "XmlDocRemarks": "https://en.wikipedia.org/wiki/Astronomical_unit",
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": [ "au", "ua" ]
+        }
+      ]
+    },
+    {
+      "SingularName": "Parsec",
+      "PluralName": "Parsecs",
+      "FromUnitToBaseFunc": "x * 3.08567758128e16",
+      "FromBaseToUnitFunc": "x / 3.08567758128e16",
+      "XmlDocSummary": "A parsec is defined as the distance at which one astronomical unit (AU) subtends an angle of one arcsecond.",
+      "XmlDocRemarks": "https://en.wikipedia.org/wiki/Parsec",
+      "Prefixes": [ "Kilo", "Mega" ],
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": [ "pc" ]
+        }
+      ]
+    },
+    {
+      "SingularName": "LightYear",
+      "PluralName": "LightYears",
+      "FromUnitToBaseFunc": "x * 9.46073047258e15",
+      "FromBaseToUnitFunc": "x / 9.46073047258e15",
+      "XmlDocSummary": "A Light Year (ly) is the distance that light travel during an Earth year, ie 365 days.",
+      "XmlDocRemarks": "https://en.wikipedia.org/wiki/Light-year",
+      "Prefixes": [ "Kilo", "Mega" ],
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": [ "ly" ]
+        }
+      ]
     }
   ]
 }

Common/UnitDefinitions/Luminosity.json

@@ -0,0 +1,40 @@
+{
+  "Name": "Luminosity",
+  "BaseUnit": "Watt",
+  "BaseType": "double",
+  "XmlDoc": "Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object.",
+  "XmlDocRemarks": "https://en.wikipedia.org/wiki/Luminosity",
+  "BaseDimensions": {
+    "L": 2,
+    "M": 1,
+    "T": -3
+  },
+  "Units": [
+    {
+      "SingularName": "Watt",
+      "PluralName": "Watts",
+      "FromUnitToBaseFunc": "x",
+      "FromBaseToUnitFunc": "x",
+      "Prefixes": [ "Femto", "Pico", "Nano", "Micro", "Milli", "Deci", "Deca", "Kilo", "Mega", "Giga", "Tera", "Peta" ],
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": [ "W" ]
+        }
+      ]
+    },
+    {
+      "SingularName": "SolarLuminosity",
+      "PluralName": "SolarLuminosities",
+      "FromUnitToBaseFunc": "x * 3.846e26",
+      "FromBaseToUnitFunc": "x / 3.846e26",
+      "XmlDocRemarks": "https://www.britannica.com/science/luminosity",
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": [ "L⊙" ]
+        }
+      ]
+    }
+  ]
+}

Common/UnitDefinitions/Mass.json

@@ -210,6 +210,40 @@
           "Abbreviations": [ "gr" ]
         }
       ]
+    },
+    {
+      "SingularName": "SolarMass",
+      "PluralName": "SolarMasses",
+      "BaseUnits": {
+        "M": "SolarMass"
+      },
+      "FromUnitToBaseFunc": "x * 1.98947e30",
+      "FromBaseToUnitFunc": "x / 1.98947e30",
+      "XmlDocSummary": "Solar mass is a ratio unit to the mass of the solar system star, the sun.",
+      "XmlDocRemarks": "https://en.wikipedia.org/wiki/Solar_mass",
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": [ "M⊙" ]
+        }
+      ]
+    },
+    {
+      "SingularName": "EarthMass",
+      "PluralName": "EarthMasses",
+      "BaseUnits": {
+        "M": "EarthMass"
+      },
+      "FromUnitToBaseFunc": "x * 5.9722E+24",
+      "FromBaseToUnitFunc": "x / 5.9722E+24",
+      "XmlDocSummary": "Earth mass is a ratio unit to the mass of planet Earth.",
+      "XmlDocRemarks": "https://en.wikipedia.org/wiki/Earth_mass",
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": [ "em" ]
+        }
+      ]
     }
   ]
 }

UnitsNet.Tests/CustomCode/LengthTests.cs

@@ -57,6 +57,20 @@ public class LengthTests : LengthTestsBase
 
         protected override double HandsInOneMeter => 9.8425196850393701;
 
+        protected override double AstronomicalUnitsInOneMeter => 6.6845871222684500000000000E-12;
+
+        protected override double KilolightYearsInOneMeter => 1.0570008340247000000000000E-19;
+
+        protected override double KiloparsecsInOneMeter => 3.2407790389471100000000000E-20;
+
+        protected override double LightYearsInOneMeter => 1.0570008340247000000000000E-16;
+
+        protected override double MegalightYearsInOneMeter => 1.0570008340247000000000000E-22;
+
+        protected override double MegaparsecsInOneMeter => 3.2407790389471100000000000E-23;
+
+        protected override double ParsecsInOneMeter => 3.2407790389471100000000000E-17;
+
         [ Fact]
         public void AreaTimesLengthEqualsVolume()
         {

UnitsNet.Tests/CustomCode/LuminosityTests.cs

@@ -0,0 +1,56 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by \generate-code.bat.
+//
+//     Changes to this file will be lost when the code is regenerated.
+//     The build server regenerates the code before each build and a pre-build
+//     step will regenerate the code on each local build.
+//
+//     See https://github.com/angularsen/UnitsNet/wiki/Adding-a-New-Unit for how to add or edit units.
+//
+//     Add CustomCode\Quantities\MyQuantity.extra.cs files to add code to generated quantities.
+//     Add UnitDefinitions\MyQuantity.json and run generate-code.bat to generate new units or quantities.
+//
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+// Licensed under MIT No Attribution, see LICENSE file at the root.
+// Copyright 2013 Andreas Gullberg Larsen ([email protected]). Maintained at https://github.com/angularsen/UnitsNet.
+
+using System;
+
+namespace UnitsNet.Tests.CustomCode
+{
+    public class LuminosityTests : LuminosityTestsBase
+    {
+        // Override properties in base class here
+        protected override double FemtowattsInOneWatt => 1e15;
+
+        protected override double PicowattsInOneWatt => 1e12;
+
+        protected override double NanowattsInOneWatt => 1e9;
+
+        protected override double MicrowattsInOneWatt => 1e6;
+
+        protected override double MilliwattsInOneWatt => 1e3;
+
+        protected override double DeciwattsInOneWatt => 1e1;
+
+        protected override double WattsInOneWatt => 1;
+
+        protected override double DecawattsInOneWatt => 1e-1;
+
+        protected override double KilowattsInOneWatt => 1e-3;
+
+        protected override double MegawattsInOneWatt => 1e-6;
+
+        protected override double GigawattsInOneWatt => 1e-9;
+
+        protected override double TerawattsInOneWatt => 1e-12;
+
+        protected override double PetawattsInOneWatt => 1e-15;
+
+        protected override double SolarLuminositiesInOneWatt => 2.6001040041601700000000000E-27;
+
+    }
+}

UnitsNet.Tests/CustomCode/MassTests.cs

@@ -57,6 +57,12 @@ public class MassTests : MassTestsBase
 
         protected override double ShortHundredweightInOneKilogram => 0.022046226218487758;
 
+        protected override double EarthMassesInOneKilogram => 1.6744248350691500000000000E-25;
+
+        protected override double SolarMassesInOneKilogram => 5.0264643347223100000000000E-31;
+
+        //protected override double SolarMassesTolerance => 0.1;
+
         [Fact]
         public void AccelerationTimesMassEqualsForce()
         {