COSMIC-PopSynth · TomWagg · Feb 19, 2026 · Feb 19, 2026 · Feb 19, 2026 · Feb 19, 2026
diff --git a/.github/ISSUE_TEMPLATE/feature-request.md b/.github/ISSUE_TEMPLATE/feature-request.md
@@ -0,0 +1,17 @@
+---
+name: Feature request
+about: I want to request a new feature
+title: ''
+labels: feature-request
+assignees: ''
+
+---
+
+**Describe the new feature you'd like**
+A clear and concise description of what you want to happen. E.g. "I love how this package can evolve populations, but I think a great improvement would be for it to also do my taxes."
+
+**Any suggestions for how to implement this**
+Is there a particular way you would implement this? How could this integrate into the existing code?
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
diff --git a/.github/ISSUE_TEMPLATE/general_issue.md b/.github/ISSUE_TEMPLATE/general_issue.md
diff --git a/.github/ISSUE_TEMPLATE/new-prescription.md b/.github/ISSUE_TEMPLATE/new-prescription.md
@@ -0,0 +1,17 @@
+---
+name: New physics prescription
+about: I want to request/suggest a new physics prescription
+title: ''
+labels: new-prescription
+assignees: ''
+
+---
+
+**Describe the new physics prescription you want to add**
+TODO
+
+**Link to the publication this is based on**
+TODO
+
+**Is this a new option for an existing flag? Or would require a new setting?**
+TODO
diff --git a/.github/ISSUE_TEMPLATE/question.md b/.github/ISSUE_TEMPLATE/question.md
@@ -0,0 +1,10 @@
+---
+name: Question
+about: I want to ask a question about COSMIC
+title: ''
+labels: question
+assignees: ''
+
+---
+
+Use this issue to ask any questions about how functions work, how best to use the package for your project or anything else you need help with! Wherever possible please include code examples to make it easier to help you!
diff --git a/.github/ISSUE_TEMPLATE/unexpected-stellar-evolutionary-behavior.md b/.github/ISSUE_TEMPLATE/unexpected-stellar-evolutionary-behavior.md
@@ -1,19 +1,48 @@
 ---
 name: Unexpected Stellar Evolutionary Behavior
-about: Way to systematically track weird evoltuionary behavior and things tried to
-  resolve that behavior for better history tracking.
-title: "[Unexpected Evolutionary Behavior]"
+about: I want to report some weird evolutionary behavior and things tried to resolve that behavior for better history tracking.
+title: ""
 labels: Unexpected Evolutionary Behavior
 assignees: ''
 
 ---
 
-# CSV file with Initial Conditions and BSE flags creating this behavior
+# Checklist
+- [ ] Attached CSV file with initial conditions and BSE flags for reproducing this behavior
+- [ ] Included code that produces the BPP/BCM arrays
+- [ ] Written description of weird behavior
+- [ ] Explained expected outcome
+- [ ] Listed flags you have tried to turn on and off that you think relate to the evolutionary behavior
+- [ ] Attached a plot if applicable
+
+# CSV file 
+
+Attach file with initC file here. You can save this like
+```python
+# create CSV file
+initC.to_csv('weird_behavior.csv', index=False)
+
+# now attach it to this issue!
+```
 
 # Code that produces the BPP and BCM arrays
 
-# Description of Weird Behavior
+```python
+# your code here
+```
+
+# Description
+
+Add a description of the weird behavior you've seen
 
-# Flags you have tried to turn on and off that you think relate to the evolutionary behavior
+# Expect outcome
+
+How do you think this system _should_ evolve?
+
+# Flags
+
+Which flag have you tried to turn on and off that you think relate to the evolutionary behavior?
 
 # Plot (if applicable)
+
+Plot goes here
diff --git a/changelog.md b/changelog.md
@@ -77,7 +77,11 @@ See the discussed changes in our previous releases here: https://github.com/COSM
  - Bug fix [[#725](https://github.com/COSMIC-PopSynth/COSMIC/issues/725)]: set ``tb=sep=0`` for cases where AIC caused a WD to explode and leave behind no remnant (``evolve_type==9``)
  - Bug fix [[#724](https://github.com/COSMIC-PopSynth/COSMIC/issues/724)]: remove bug where ``kstar=15`` was assigned its previous epoch mass after merging during a CE and the merger product goes SN
 
-## 3.7.2
+## 3.7.2-3.7.3
+
+Issues with PyPi, unreleased.
+
+## 3.7.4
 This release contains _several_ fixes to how CO core masses/remnant masses are handled. It also adds a new PISN prescription, windflag and LBV winds flag.
 
 - Fixes:
@@ -88,6 +92,7 @@ This release contains _several_ fixes to how CO core masses/remnant masses are h
     - Update ``mc = mt`` for **ALL** remnants instead of just for certain flags
     - Only apply conversion from baryonic to gravitational mass once. Previous code **APPLIED IT TWICE!!** for core-collapse BHs! Create subroutine ``baryonic_to_gravitational_mass``, which is called throughout
     - Ensure stellar type changes during hrdiag are logged to the bpp before SN occurs
+    - Add check after CE for whether a SN occurs right at the end
 
 - Additions/changes:
     - Linearly grow the core mass of HeMS stars from 0 to the value at the start of HeHG and check for core-collapse for all He stars (not just HeHG and HeGB)

diff --git a/src/cosmic/_version.py b/src/cosmic/_version.py
@@ -1 +1 @@
-__version__ = "3.7.2"
+__version__ = "3.7.4"
diff --git a/src/cosmic/evolve.py b/src/cosmic/evolve.py
@@ -184,6 +184,8 @@ def evolve(self, initialbinarytable, pool=None, bpp_columns=None, bcm_columns=No
             are logged in the initial conditions table so you can keep track of which systems had their
             timesteps modified. Avoid overlapping mass ranges for different modifiers as this will result
             in multiple modifiers being applied in the overlap region.
+            NOTE: these modifiers are only applied to columns which aren't present in the initialbinarytable
+            that is passed in (i.e. they only modify values provided by a BSEDict or params.ini file)
 
         **kwargs:
             There are three ways to tell evolve and thus the fortran
@@ -250,6 +252,8 @@ def evolve(self, initialbinarytable, pool=None, bpp_columns=None, bcm_columns=No
         if bcm_columns is None:
             bcm_columns = BCM_COLUMNS
 
+        columns_in_passed_initC = set(initialbinarytable.columns)
+
         # There are three ways to tell evolve and thus the fortran
         # what you want all the flags and other BSE specific
         # parameters to be
@@ -383,7 +387,8 @@ def evolve(self, initialbinarytable, pool=None, bpp_columns=None, bcm_columns=No
             initialbinarytable = initialbinarytable.assign(fprimc_array=initialbinarytable[FPRIMC_COLUMNS].values.tolist())
 
         # update timesteps based on mass modifier
-        if dt_mass_modifiers:
+        mass_modifier_cols = set(['pts1', 'pts2', 'pts3']).difference(columns_in_passed_initC)
+        if dt_mass_modifiers and len(mass_modifier_cols) != 0:
             # warn the user if their mass ranges overlap
             for i in range(len(dt_mass_modifiers)):
                 for j in range(i + 1, len(dt_mass_modifiers)):
@@ -405,9 +410,8 @@ def evolve(self, initialbinarytable, pool=None, bpp_columns=None, bcm_columns=No
                     raise ValueError(f"Timestep modifiers must be positive. You passed {mod} for the "
                                      f"mass range {m_low} to {m_high}.")
                 mask = (initialbinarytable['mass_1'] >= m_low) & (initialbinarytable['mass_1'] < m_high)
-                initialbinarytable.loc[mask, 'pts1'] *= mod
-                initialbinarytable.loc[mask, 'pts2'] *= mod
-                initialbinarytable.loc[mask, 'pts3'] *= mod
+                for col in mass_modifier_cols:
+                    initialbinarytable.loc[mask, col] *= mod
 
         # need to ensure that the order of parameters that we pass to BSE
         # is correct

diff --git a/src/cosmic/src/evolv2.f b/src/cosmic/src/evolv2.f
@@ -2495,36 +2495,143 @@ SUBROUTINE evolv2(kstar,mass,tb,ecc,z,tphysf,
             formation(j1) = formation(j2)
          endif
 
+* Calculate stellar properties for both stars
+         do 117, k = 1,2
+         m0 = mass0(k)
+         mt = mass(k)
+         mc = massc(k)
+         kw = kstar(k)
+         CALL star(kw,m0,mt,tm,tn,tscls,lums,GB,zpars)
+         CALL hrdiag(m0,aj(k),mt,tm,tn,tscls,lums,GB,zpars,
+     &               rm,lum,kw,mc,rc,me,re,k2,bhspin(k),k)
+
+*
+* Check for a supernova and correct the semi-major axis if so.
+*
+         if((kw.ne.kstar(k).and.kstar(k).le.12.and.
+     &      (kw.eq.13.or.kw.eq.14
+     &       .or.(kw.eq.15.and.pisn_track(k).eq.7))))then
+            dms(k) = mass(k) - mt
+            if(formation(k).ne.11) formation(k) = 1
+            if(kw.eq.13.and.ecsn.gt.0.d0)then
+               if(kstar(k).le.6)then
+                  if(mass0(k).le.zpars(5))then
+                     if(sigma.gt.0.d0.and.sigmadiv.gt.0.d0)then
+                        sigma = -sigmahold/sigmadiv
+                     elseif(sigma.gt.0.d0.and.sigmadiv.lt.0.d0)then
+                        sigma = sigmadiv
+                     endif
+                     formation(k) = 2
+                  endif
+               elseif(kstar(k).ge.7.and.kstar(k).le.9)then
+                  if(mass(k).gt.ecsn_mlow.and.mass(k).le.ecsn)then
+                     if(sigma.gt.0.d0.and.sigmadiv.gt.0.d0)then
+                        sigma = -sigmahold/sigmadiv
+                     elseif(sigma.gt.0.d0.and.sigmadiv.lt.0.d0)then
+                        sigma = sigmadiv
+                     endif
+                     formation(k) = 2
+                  endif
+               elseif(formation(k).eq.11)then
+                  if(sigma.gt.0.d0.and.sigmadiv.gt.0.d0)then
+                     sigma = -sigmahold/sigmadiv
+                  elseif(sigma.gt.0.d0.and.sigmadiv.lt.0.d0)then
+                     sigma = sigmadiv
+                  endif
+                  formation(k) = 5
+               elseif(kstar(k).ge.10.or.kstar(k).eq.12)then
+                  if(sigma.gt.0.d0.and.sigmadiv.gt.0.d0)then
+                     sigma = -sigmahold/sigmadiv
+                  elseif(sigma.gt.0.d0.and.sigmadiv.lt.0.d0)then
+                     sigma = sigmadiv
+                  endif
+                  formation(k) = 4
+               endif
+            endif
+
+            evolve_type = 14.d0 + FLOAT(k)
+            teff1 = 1000.d0*((1130.d0*lumin(1)/
+     &                       (rad(1)**2.d0))**(1.d0/4.d0))
+            teff2 = 1000.d0*((1130.d0*lumin(2)/
+     &                       (rad(2)**2.d0))**(1.d0/4.d0))
+            if(B_0(1).eq.0.d0)then !PK.
+               b01_bcm = 0.d0
+            elseif(B_0(1).gt.0.d0.and.B(1).eq.0.d0)then
+               b01_bcm = B_0(1)
+            else
+               b01_bcm = B(1)
+            endif
+            if(B_0(2).eq.0.d0)then
+               b02_bcm = 0.d0
+            elseif(B_0(2).gt.0.d0.and.B(2).eq.0.d0)then
+               b02_bcm = B_0(2)
+            else
+               b02_bcm = B(2)
+            endif
+
+* Check if PISN occurred, and if so overwrite formation
+            if(pisn_track(1).ne.0) formation(1) = pisn_track(1)
+            if(pisn_track(2).ne.0) formation(2) = pisn_track(2)
+
+            CALL writetab(bpp_ind,tphys,evolve_type,
+     &                    mass(1),mass(2),kstar(1),kstar(2),
+     &                    sep,tb,ecc,rrl1,rrl2,
+     &                    aj(1),aj(2),tms(1),tms(2),
+     &                    mc_he(1),mc_he(2),mc_co(1),mc_co(2),
+     &                    rad(1),rad(2),
+     &                    mass0(1),mass0(2),lumin(1),lumin(2),
+     &                    teff1,teff2,radc(1),radc(2),
+     &                    menv(1),menv(2),renv(1),renv(2),
+     &                    ospin(1),ospin(2),b01_bcm,b02_bcm,
+     &                    bacc(1),bacc(2),tacc(1),tacc(2),epoch(1),
+     &                    epoch(2),bhspin(1),bhspin(2),
+     &                    deltam1_bcm,deltam2_bcm,formation(1),
+     &                    formation(2),binstate,mergertype,z,'bpp')
+            CALL kick(kw,mass(k),mc_co(k),mt,mass(3-k),ecc,sep,jorb,vk,
+     &                k,rad(3-k),fallback,sigmahold,kick_info,
+     &                disrupt,bkick)
+            sigma = sigmahold
+
+            ! check if kick caused a merger
+            if(mass(3-k).lt.0.d0)then
+               if(kstar(3-k).lt.0.d0) mt = mt-mass(3-k)
+               if(kw.eq.13.and.mt.gt.mxns) kw = 14
+               CALL CONCATKSTARS(kstar(j1), kstar(j2), mergertype)
+               kstar(k) = kw
+               mass(k) = mt
+               epoch(k) = tphys - age
+               kstar(3-k) = 15
+               mass(3-k) = 0.d0
+               coel = .true.
+               binstate = 1
+            endif
+
+            if(ecc.gt.1.d0)then
+               tb = -1d0
+               sep = -1d0
+               oorb = -1d0
+            else
+               tb = (sep/aursun)*SQRT(sep/(aursun*(mt+mass(3-k))))
+               oorb = twopi/tb
+            endif
+         endif
+
+         mass0(k) = m0
+         mass(k) = mt
+         massc(k) = mc
+         kstar(k) = kw
+         rad(k) = rm
+         lumin(k) = lum  
+         radc(k) = rc
+         menv(k) = me
+         renv(k) = re
+
+
+117      continue
+
 *
          evolve_type = 8.0
-
-
-         mc = massc(1)
-         rc = radc(1)
-         CALL star(kstar(1),mass0(1),mass(1),tm,tn,tscls,lums,GB,zpars)
-         CALL hrdiag(mass0(1),aj(1),mass(1),tm,tn,tscls,lums,GB,zpars,
-     &               rm,lum,kstar(1),mc,rc,me,re,k2,bhspin(1),1)
-
-         rad(1) = rm
-         lumin(1) = lum  
-         massc(1) = mc
-         radc(1) = rc
-         menv(1) = me
-         renv(1) = re
-
-
-         mc = massc(2)
-         rc = radc(2)
-         CALL star(kstar(2),mass0(2),mass(2),tm,tn,tscls,lums,GB,zpars)
-         CALL hrdiag(mass0(2),aj(2),mass(2),tm,tn,tscls,lums,GB,zpars,
-     &               rm,lum,kstar(2),mc,rc,me,re,k2,bhspin(2),2)
-
-         rad(2) = rm
-         lumin(2) = lum  
-         massc(2) = mc
-         radc(2) = rc
-         menv(2) = me
-         renv(2) = re
+
 
          mass1_bpp = mass(1)
          mass2_bpp = mass(2)