[Kstars-devel] KDE/kdeedu/kstars/kstars

[Akarsh Simha]

SVN commit 911005 by asimha:

Reverting changes in the magnitude formula for asteroids. The earlier
magnitude formula was general, although I found it being used in the
context of Encke on Seichii Yoshida's page. It seems (from the Cartes
du Ciel sources) that the correct formulas as indicated by Meeus are
the ones used now.

CCMAIL: kstars-devel at kde.org



 M  +17 -15    ksplanetbase.cpp  


--- trunk/KDE/kdeedu/kstars/kstars/ksplanetbase.cpp #911004:911005
@@ -339,22 +339,24 @@
     if( name() == i18n( "Pluto" ) )
         magnitude = -1.01 + param + 0.041*phase;
 
-    if( type() == SkyObject::ASTEROID || type() == SkyObject::COMET ) {
-        // Asteroid or Comet
+    if( type() == SkyObject::ASTEROID ) {
+        // Asteroid
         double H, G;
-        if( type() == SkyObject::ASTEROID ) {
-            KSAsteroid *me = (KSAsteroid *)this;
-            H = me -> getAbsoluteMagnitude();
-            G = me -> getSlopeParameter();
-        }
-        else {
-            KSComet *me = (KSComet *) this;
-            H = me -> getAbsoluteMagnitude();
-            G = me -> getSlopeParameter();
-        }
-        if( H > -100.0 && G > -100.0 ) {
-            magnitude = H + 5 * log10( rearth() ) + 2.5 * G * log10( rsun() );
-        }
+        double phi1 = exp( -3.33 * pow( tan( phase_rad / 2 ), 0.63 ) );
+        double phi2 = exp( -1.87 * pow( tan( phase_rad / 2 ), 1.22 ) );
+        KSAsteroid *me = (KSAsteroid *)this;
+        H = me -> getAbsoluteMagnitude();
+        G = me -> getSlopeParameter();
+        magnitude = H + param - 2.5 * log( (1 - G) * phi1 + G * phi2 );
     }
+
+    if( type() == SkyObject::COMET ) {
+        // Comet
+        double H, G;
+        KSComet *me = (KSComet *)this;
+        H = me -> getAbsoluteMagnitude();
+        G = me -> getSlopeParameter();
+        magnitude = H + 5.0 * log10( rearth() ) + 2.5 * G * log10( rsun() );
+    }
     setMag(magnitude);
 }