Spin retention after envelope loss

src/BaseBinaryStar.cpp

@@ -1465,6 +1465,8 @@ void BaseBinaryStar::ResolveCommonEnvelopeEvent() {
     double periastronRsol    = PeriastronRsol();                                                                        // periastron, Rsol (before CEE)
     double rRLd1Rsol         = periastronRsol * CalculateRocheLobeRadius_Static(m_Star1->Mass(), m_Star2->Mass());      // Roche-lobe radius at periastron in Rsol at the moment where CEE begins, seen by star1
     double rRLd2Rsol         = periastronRsol * CalculateRocheLobeRadius_Static(m_Star2->Mass(), m_Star1->Mass());      // Roche-lobe radius at periastron in Rsol at the moment where CEE begins, seen by star2
+    double omegaSpin1_pre_CE = m_Star1->Omega();                                                                        // star1 spin (before CEE)
+    double omegaSpin2_pre_CE = m_Star2->Omega();                                                                        // star2 spin (before CEE)
 
     bool isDonorMS = false;                                                                                             // check for main sequence donor
     if (OPTIONS->AllowMainSequenceStarToSurviveCommonEnvelope()) {                                                      // allow main sequence stars to survive CEE?
@@ -1642,11 +1644,13 @@ void BaseBinaryStar::ResolveCommonEnvelopeEvent() {
 
         if (envelopeFlag1) {
             m_Star1->ResolveEnvelopeLossAndSwitch();                                                                    // resolve envelope loss for star1 and switch to new stellar type
+            m_Star1->SetOmega(omegaSpin1_pre_CE);                                                                       // keep the rotation frequency of the core equal to the pre-envelope-loss rotation frequency
             m_MassTransferTrackerHistory = MT_TRACKING::CE_1_TO_2_SURV;
         }
 
         if (envelopeFlag2) {
             m_Star2->ResolveEnvelopeLossAndSwitch();                                                                    // resolve envelope loss for star1 and switch to new stellar type
+            m_Star2->SetOmega(omegaSpin2_pre_CE);                                                                       // keep the rotation frequency of the core equal to the pre-envelope-loss rotation frequency
             m_MassTransferTrackerHistory = MT_TRACKING::CE_2_TO_1_SURV;
         }
 

src/Star.cpp

@@ -180,16 +180,11 @@ bool Star::RevertState() {
  *
  * Resolve the loss of an envelope, including switching the stellar type.
  *
- * Keep the rotation frequency of the core equal to the pre-envelope-loss rotation frequency
- * (envelope loss is rapid, so no time for angular momentum transport)
- *
  * void ResolveEnvelopeLossAndSwitch()
  *
  */
 void Star::ResolveEnvelopeLossAndSwitch() {
-    double omega = Omega();
     (void)SwitchTo(m_Star->ResolveEnvelopeLoss(true));
-    SetOmega(omega);
 }
 
 

src/changelog.h

@@ -1391,7 +1391,8 @@
 //                                      - Added new critical mass ratio tables for He stars from Ge et al. team
 //                                      - Cleaned up the stability calculation for H-rich stars as well, specifically implementing nearest neighbor for extrapolation
 //                                      - Now all of their results from Papers I-V are included (including those requested in private comm.)
-
-const std::string VERSION_STRING = "03.08.02";
+// 03.08.03   VK - Nov 20, 2024     - Defect repairs
+//                                      - Fixed behavior for core spin to be retained after envelope loss.
+const std::string VERSION_STRING = "03.08.03";
 
 # endif // __changelog_h__