Bug fixes in tides, helium giant updates, white dwarf radii and McBGB calculations

src/BaseBinaryStar.cpp

@@ -2086,6 +2086,8 @@ void BaseBinaryStar::CalculateMassTransfer(const double p_Dt) {
                                                                                                                                 // no
             m_MassTransferTrackerHistory = m_Donor == m_Star1 ? MT_TRACKING::STABLE_1_TO_2_SURV : MT_TRACKING::STABLE_2_TO_1_SURV;  // record what happened - for later printing
             double massGainAccretor = -massDiffDonor * m_FractionAccreted;                                                      // set accretor mass gain to mass loss * conservativeness
+
+            double omegaDonor_pre_MT = m_Donor->Omega();                                                                        // used if full donor envelope is removed
 
             m_Donor->SetMassTransferDiffAndResolveWDShellChange(massDiffDonor);                                                 // set new mass of donor
             m_Accretor->SetMassTransferDiffAndResolveWDShellChange(massGainAccretor);                                           // set new mass of accretor
@@ -2095,7 +2097,12 @@ void BaseBinaryStar::CalculateMassTransfer(const double p_Dt) {
             m_aMassTransferDiff = aFinal - aInitial;                                                                            // set change in orbit (semi-major axis)
 
             STELLAR_TYPE stellarTypeDonor = m_Donor->StellarType();                                                             // donor stellar type before resolving envelope loss
-            if (isEnvelopeRemoved) m_Donor->ResolveEnvelopeLossAndSwitch();                                                     // if this was an envelope stripping episode, resolve envelope loss
+
+            if (isEnvelopeRemoved) {                                                                                            // if this was an envelope stripping episode, resolve envelope loss
+                m_Donor->ResolveEnvelopeLossAndSwitch();                                                                        // resolve envelope loss for the donor and switch to new stellar type
+                m_Donor->SetOmega(omegaDonor_pre_MT);                                                                           // keep the rotation frequency of the core equal to the pre-envelope-loss rotation frequency
+            }
+
             if (m_Donor->StellarType() != stellarTypeDonor) {                                                                   // stellar type change?
                 (void)PrintDetailedOutput(m_Id, BSE_DETAILED_RECORD_TYPE::STELLAR_TYPE_CHANGE_DURING_MT);                       // yes - print (log) detailed output
             }
@@ -2437,6 +2444,7 @@ void BaseBinaryStar::ResolveMassChanges() {
     if (utils::Compare(m_Star1->MassPrev(), m_Star1->Mass()) == 0) {                                    // mass already updated?
                                                                                                         // no - resolve mass changes      
         double massChange = m_Star1->MassLossDiff() + m_Star1->MassTransferDiff();                      // mass change due to winds and mass transfer
+
         if (utils::Compare(massChange, 0.0) != 0) {                                                     // winds/mass transfer changes mass?
             // yes - calculate new angular momentum; assume accretor is adding angular momentum from a circular orbit at the stellar radius
             double angularMomentumChange = (utils::Compare(massChange, 0.0) > 0) ?

src/BaseStar.cpp

@@ -2844,7 +2844,7 @@ void BaseStar::ResolveMassLoss(const bool p_UpdateMDt) {
         UpdateInitialMass();                                                                        // update effective initial mass (MS, HG & HeMS)
         UpdateAgeAfterMassLoss();                                                                   // update age (MS, HG & HeMS)
         ApplyMassTransferRejuvenationFactor();                                                      // apply age rejuvenation factor
-        SetAngularMomentum(m_AngularMomentum + angularMomentumChange);                              
+        SetAngularMomentum(m_AngularMomentum + angularMomentumChange);
     }
 }
 

src/GiantBranch.cpp

@@ -770,10 +770,12 @@ double GiantBranch::CalculateCoreMassAtBGB(const double p_Mass, const DBL_VECTOR
 #define gbParams(x) p_GBParams[static_cast<int>(GBP::x)]                // for convenience and readability - undefined at end of function
 #define massCutoffs(x) m_MassCutoffs[static_cast<int>(MASS_CUTOFF::x)]  // for convenience and readability - undefined at end of function
 
+    if (utils::Compare(p_Mass, massCutoffs(MHeF)) <= 0)     return 0.0;                                                 // No McBGB for stars with mass below the helium flash threshold, see text above Eq. (44) of Hurley+ (2000)
+
     double luminosity = GiantBranch::CalculateLuminosityAtPhaseBase_Static(massCutoffs(MHeF), m_AnCoefficients);
     double Mc_MHeF    = BaseStar::CalculateCoreMassGivenLuminosity_Static(luminosity, p_GBParams);
     double c          = (Mc_MHeF * Mc_MHeF * Mc_MHeF * Mc_MHeF) - (MC_L_C1 * PPOW(massCutoffs(MHeF), MC_L_C2));         // pow() is slow - use multiplication
-
+    
     return std::min((0.95 * gbParams(McBAGB)), std::sqrt(std::sqrt(c + (MC_L_C1 * PPOW(p_Mass, MC_L_C2)))));            // sqrt is much faster than PPOW()
 
 #undef massCutoffs

src/HeHG.cpp

@@ -114,7 +114,7 @@ void HeHG::CalculateGBParams_Static(const double      p_Mass0,
                                           DBL_VECTOR &p_GBParams) {
 
 #define gbParams(x) p_GBParams[static_cast<int>(GBP::x)]    // for convenience and readability - undefined at end of function
-
+    
     GiantBranch::CalculateGBParams_Static(p_Mass, p_LogMetallicityXi, p_MassCutoffs, p_AnCoefficients, p_BnCoefficients, p_GBParams);                                     // calculate common values (actually, all)
 
     // recalculate HeHG specific values
@@ -125,6 +125,12 @@ void HeHG::CalculateGBParams_Static(const double      p_Mass0,
     gbParams(Mx)     = GiantBranch::CalculateCoreMass_Luminosity_Mx_Static(p_GBParams);      // depends on B, D, p & q - recalculate if any of those are changed
     gbParams(Lx)     = GiantBranch::CalculateCoreMass_Luminosity_Lx_Static(p_GBParams);      // depends on B, D, p, q & Mx - recalculate if any of those are changed
 
+    // need to reset p and q to HeHG specific versions -- while they are set in GiantBranch::CalculateGBParams_Static(), that uses
+    // the GiantBranch versions of CalculateCoreMass_Luminosity_p_Static and CalculateCoreMass_Luminosity_q_Static
+    // should return to this and understand desired behavior - *ILYA*
+    gbParams(p) = CalculateCoreMass_Luminosity_p_Static(p_Mass, p_MassCutoffs);
+    gbParams(q) = CalculateCoreMass_Luminosity_q_Static(p_Mass, p_MassCutoffs);
+
 	gbParams(McBAGB) = p_Mass0;
 	gbParams(McBGB)  = GiantBranch::CalculateCoreMassAtBGB_Static(p_Mass, p_MassCutoffs, p_AnCoefficients, p_GBParams);
 

src/WhiteDwarfs.cpp

@@ -155,6 +155,8 @@ double WhiteDwarfs::CalculateRadiusOnPhase_Static(const double p_Mass) {
     // sanity check for mass - just return 0.0 if mass <= 0
     if (utils::Compare(p_Mass, 0.0) <= 0) return 0.0;
 
+    if (utils::Compare(p_Mass, MCH) >= 0) return NEUTRON_STAR_RADIUS;                               // only expected to come up if asking for the core or remnant radius of a giant star
+
     double MCH_Mass_one_third  = std::cbrt(MCH / p_Mass); 
     double MCH_Mass_two_thirds = MCH_Mass_one_third * MCH_Mass_one_third;
 

src/changelog.h

@@ -1411,6 +1411,11 @@
 //                                      - Minor fixes, including to #1255, #1258
 // 03.10.00   JR - Nov 29, 2024     - Enhancement:
 //                                      - added functionality to allow stellar mergers (for BSE) to be logged to switchlog file (see documentation for details)
-const std::string VERSION_STRING = "03.10.00";
+// 03.10.01   IM - Nov 30, 2024     - Defect repair:
+//                                      - corrected treatment of rotation to retain pre-mass-loss spin frequency, not angular momentum, on complete envelope removal during stable mass transfer
+//                                      - fixed issue with updating helium giants that manifested as supernovae with nan core mass (see #1245)
+//                                      - added check for exceeding Chandrasekhar mass when computing white dwarf radius (resolves issue #1264)
+//                                      - added check to only compute McBGB for stars with mass above MHeF, following text above Eq. 44 in Hurley+, 2000 (resolves issue #1256)
+const std::string VERSION_STRING = "03.10.01";
 
 # endif // __changelog_h__