VirtualPlanetaryLaboratory · RoryBarnes · May 27, 2026 · May 21, 2026
diff --git a/src/stellar.c b/src/stellar.c
@@ -269,11 +269,13 @@ void ReadXUVModel(BODY *body, CONTROL *control, FILES *files, OPTIONS *options,
       body[iFile - 1].iXUVModel = STELLAR_MODEL_ENGLE24EARLY;
     } else if (!memcmp(sLower(cTmp), "engle24m", 8)) {
       body[iFile - 1].iXUVModel = STELLAR_MODEL_ENGLE24MIDLATE;
+    } else if (!memcmp(sLower(cTmp), "engle24a", 8)) {
+      body[iFile - 1].iXUVModel = STELLAR_MODEL_ENGLE24AUTO;
     } else {
       if (control->Io.iVerbose >= VERBERR) {
         fprintf(stderr,
                 "ERROR: Unknown argument to %s: %s. Options are RIBAS, REINERS, "
-                "ENGLE24EARLY, ENGLE24MIDLATE, or NONE.\n",
+                "ENGLE24EARLY, ENGLE24MIDLATE, ENGLE24AUTO, or NONE.\n",
                 options->cName, cTmp);
       }
       LineExit(files->Infile[iFile].cIn, lTmp);
@@ -1677,6 +1679,17 @@ void fnPropsAuxStellar(BODY *body, EVOLVE *evolve, IO *io, UPDATE *update,
     body[iBody].dLXUV = fdLXUVEngle(
           body, body[iBody].dXUVEngleMidLateA, body[iBody].dXUVEngleMidLateB,
           body[iBody].dXUVEngleMidLateC, body[iBody].dXUVEngleMidLateD, iBody);
+  } else if (body[iBody].iXUVModel == STELLAR_MODEL_ENGLE24AUTO) {
+    /* Per-timestep dispatch on stellar mass.  Boundary at 0.4 Msun. */
+    if (body[iBody].dMass >= 0.4 * MSUN) {
+      body[iBody].dLXUV = fdLXUVEngle(
+            body, body[iBody].dXUVEngleEarlyA, body[iBody].dXUVEngleEarlyB,
+            body[iBody].dXUVEngleEarlyC, body[iBody].dXUVEngleEarlyD, iBody);
+    } else {
+      body[iBody].dLXUV = fdLXUVEngle(
+            body, body[iBody].dXUVEngleMidLateA, body[iBody].dXUVEngleMidLateB,
+            body[iBody].dXUVEngleMidLateC, body[iBody].dXUVEngleMidLateD, iBody);
+    }
   } else {
 
     // Constant XUV fraction
@@ -1904,12 +1917,29 @@ void VerifyXUVEngleMidLate(BODY *body, CONTROL *control, FILES *files,
                               OPT_XUVMODEL, OPT_XUVENGLEEARLYD, iBody);
 }
 
+void VerifyXUVEngleAuto(BODY *body, CONTROL *control, FILES *files,
+                        OPTIONS *options, int iBody) {
+  /* Engle24Auto: pick Early or MidLate per-timestep based on dMass.  Allow
+     up to 25% extrapolation outside the calibrated union range
+     [0.1, 0.6] M_sun, but exit for masses more than 25% out of bounds. */
+  char cModel[LINE] = "ENGLE24AUTO XUV";
+  double dMinSafe   = 0.075;
+  double dMaxSafe   = 0.750;
+
+  VerifyEngleMassSpectralType(body, control, files, options, cModel,
+                              dMaxSafe, dMinSafe, OPT_XUVMODEL, iBody);
+  /* No VerifyTwoEngleOptionsNotSet calls — Auto requires BOTH Early
+     and MidLate coefficient blocks to be present in star.in. */
+}
+
 void VerifyXUVEngle(BODY *body, CONTROL *control, FILES *files,
                     OPTIONS *options, int iBody) {
   if (body[iBody].iXUVModel == STELLAR_MODEL_ENGLE24EARLY) {
     VerifyXUVEngleEarly(body, control, files, options, iBody);
   } else if (body[iBody].iXUVModel == STELLAR_MODEL_ENGLE24MIDLATE) {
     VerifyXUVEngleMidLate(body, control, files, options, iBody);
+  } else if (body[iBody].iXUVModel == STELLAR_MODEL_ENGLE24AUTO) {
+    VerifyXUVEngleAuto(body, control, files, options, iBody);
   }
 }
 

diff --git a/src/stellar.h b/src/stellar.h
@@ -45,6 +45,11 @@
   7 /**< XUV evolution from Engle (2024) for M0-M2 dwarfs */
 #define STELLAR_MODEL_ENGLE24MIDLATE                                           \
   8 /**< XUV evolution from Engle (2024) for M2.6-M6.5 dwarfs */
+#define STELLAR_MODEL_ENGLE24AUTO                                              \
+  9 /**< XUV evolution from Engle (2024) with per-timestep model selection \
+       based on stellar mass.  Both Early and MidLate coefficient sets must \
+       be provided in star.in; dispatch uses Early for dMass >= 0.4 Msun, \
+       MidLate otherwise.  Mass safety bound: 0.075 < dMass < 0.75 Msun. */
 
 #define STELLAR_DJDT_NONE                                                      \
   0 /**< No stellar angular momentum loss via magnetic braking */

diff --git a/tests/Stellar/EngleAutoEarly/star.in b/tests/Stellar/EngleAutoEarly/star.in
@@ -0,0 +1,30 @@
+# Engle24Auto -- Early dispatch test fixture (M = 0.5 Msun).
+# At M = 0.5 > 0.40 Msun, Auto-mode dispatch must select the Early
+# coefficient set.  Companion fixture `star_early.in` runs the same setup
+# with sXUVModel = Engle24Early directly; the test asserts the resulting
+# .log files agree, proving dispatch correctness in the Early regime.
+
+sName               star
+saModules           stellar
+
+dMass               0.5
+dRotPeriod          -10
+dAge                1e9
+
+sStellarModel       baraffe
+sXUVModel           Engle24Auto
+sMagBrakingModel    reiners
+
+# Engle (2024) Early coefficients (active for M = 0.5 >= 0.4)
+dXUVEngleEarlyA     -0.4896
+dXUVEngleEarlyB     -3.2128
+dXUVEngleEarlyC     -0.4469
+dXUVEngleEarlyD     -0.2985
+
+# Engle (2024) MidLate coefficients (present but unused for M=0.5)
+dXUVEngleMidLateA   -0.1456
+dXUVEngleMidLateB   -2.8876
+dXUVEngleMidLateC   -1.8187
+dXUVEngleMidLateD    0.3545
+
+saOutputOrder Time -Luminosity -LXUVStellar -LXUVTot
diff --git a/tests/Stellar/EngleAutoEarly/test_EngleAutoEarly.py b/tests/Stellar/EngleAutoEarly/test_EngleAutoEarly.py
@@ -0,0 +1,78 @@
+from benchmark import Benchmark, benchmark 
+import astropy.units as u 
+
+@benchmark( 
+   { 
+       "log.initial.system.Age": {"value": 3.155760e+16, "unit": u.sec}, 
+       "log.initial.system.Time": {"value": 0.000000, "unit": u.sec}, 
+       "log.initial.system.TotAngMom": {"value": 1.316702e+41, "unit": (u.kg * u.m ** 2) / u.sec}, 
+       "log.initial.system.TotEnergy": {"value": -1.236883e+41, "unit": u.Joule}, 
+       "log.initial.system.PotEnergy": {"value": -1.236888e+41, "unit": u.Joule}, 
+       "log.initial.system.KinEnergy": {"value": 4.787665e+35, "unit": u.Joule}, 
+       "log.initial.system.DeltaTime": {"value": 0.000000, "unit": u.sec}, 
+       "log.initial.star.Mass": {"value": 9.942080e+29, "unit": u.kg}, 
+       "log.initial.star.Radius": {"value": 3.200220e+08, "unit": u.m}, 
+       "log.initial.star.RadGyra": {"value": 0.421689}, 
+       "log.initial.star.RotAngMom": {"value": 1.316702e+41, "unit": (u.kg * u.m ** 2) / u.sec}, 
+       "log.initial.star.RotVel": {"value": 2327.265658, "unit": u.m / u.sec}, 
+       "log.initial.star.BodyType": {"value": 0.000000}, 
+       "log.initial.star.RotRate": {"value": 7.272205e-06, "unit": 1 / u.sec}, 
+       "log.initial.star.RotPer": {"value": 8.640000e+05, "unit": u.sec}, 
+       "log.initial.star.Density": {"value": 7241.843562, "unit": u.kg / u.m ** 3}, 
+       "log.initial.star.HZLimitDryRunaway": {"value": 2.534228e+10, "unit": u.m}, 
+       "log.initial.star.HZLimRecVenus": {"value": 2.247260e+10, "unit": u.m}, 
+       "log.initial.star.HZLimRunaway": {"value": 2.975872e+10, "unit": u.m}, 
+       "log.initial.star.HZLimMoistGreenhouse": {"value": 2.973489e+10, "unit": u.m}, 
+       "log.initial.star.HZLimMaxGreenhouse": {"value": 5.547642e+10, "unit": u.m}, 
+       "log.initial.star.HZLimEarlyMars": {"value": 6.050631e+10, "unit": u.m}, 
+       "log.initial.star.Instellation": {"value": -1.000000, "unit": u.kg / u.sec ** 3}, 
+       "log.initial.star.CriticalSemiMajorAxis": {"value": -1.000000, "unit": u.m}, 
+       "log.initial.star.LXUVTot": {"value": 1.569641e-05, "unit": u.LSUN}, 
+       "log.initial.star.LostEnergy": {"value": 5.562685e-309, "unit": u.Joule}, 
+       "log.initial.star.LostAngMom": {"value": 5.562685e-309, "unit": (u.kg * u.m ** 2) / u.sec}, 
+       "log.initial.star.EscapeVelocity": {"value": 6.439704e+05, "unit": u.m / u.sec}, 
+       "log.initial.star.Luminosity": {"value": 0.034834, "unit": u.LSUN}, 
+       "log.initial.star.LXUVStellar": {"value": 1.569641e-05, "unit": u.LSUN}, 
+       "log.initial.star.Temperature": {"value": 3680.001536, "unit": u.K}, 
+       "log.initial.star.LXUVFrac": {"value": 0.000451}, 
+       "log.initial.star.RossbyNumber": {"value": 0.209553}, 
+       "log.initial.star.DRotPerDtStellar": {"value": 7.073788e-11}, 
+       "log.initial.star.WindTorque": {"value": 1.078018e+25}, 
+       "log.final.system.Age": {"value": 3.098080e+17, "unit": u.sec, "rtol": 1e-4}, 
+       "log.final.system.Time": {"value": 2.782504e+17, "unit": u.sec, "rtol": 1e-4}, 
+       "log.final.system.TotAngMom": {"value": 1.317902e+41, "unit": (u.kg * u.m ** 2) / u.sec, "rtol": 1e-4}, 
+       "log.final.system.TotEnergy": {"value": -1.235338e+41, "unit": u.Joule, "rtol": 1e-4}, 
+       "log.final.system.PotEnergy": {"value": -1.208001e+41, "unit": u.Joule, "rtol": 1e-4}, 
+       "log.final.system.KinEnergy": {"value": 4.875508e+34, "unit": u.Joule, "rtol": 1e-4}, 
+       "log.final.star.Mass": {"value": 9.942080e+29, "unit": u.kg, "rtol": 1e-4}, 
+       "log.final.star.Radius": {"value": 3.276747e+08, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.RadGyra": {"value": 0.418088, "rtol": 1e-4}, 
+       "log.final.star.RotAngMom": {"value": 4.265542e+40, "unit": (u.kg * u.m ** 2) / u.sec, "rtol": 1e-4}, 
+       "log.final.star.RotVel": {"value": 749.063438, "unit": u.m / u.sec, "rtol": 1e-4}, 
+       "log.final.star.BodyType": {"value": 0.000000, "rtol": 1e-4}, 
+       "log.final.star.RotRate": {"value": 2.285997e-06, "unit": 1 / u.sec, "rtol": 1e-4}, 
+       "log.final.star.RotPer": {"value": 2.748553e+06, "unit": u.sec, "rtol": 1e-4}, 
+       "log.final.star.Density": {"value": 6746.210879, "unit": u.kg / u.m ** 3, "rtol": 1e-4}, 
+       "log.final.star.HZLimitDryRunaway": {"value": 2.609042e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimRecVenus": {"value": 2.313092e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimRunaway": {"value": 3.063255e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimMoistGreenhouse": {"value": 3.060595e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimMaxGreenhouse": {"value": 5.708049e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimEarlyMars": {"value": 6.225591e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.Instellation": {"value": -1.000000, "unit": u.kg / u.sec ** 3, "rtol": 1e-4}, 
+       "log.final.star.CriticalSemiMajorAxis": {"value": -1.000000, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.LXUVTot": {"value": 1.959178e-06, "unit": u.LSUN, "rtol": 1e-4}, 
+       "log.final.star.LostEnergy": {"value": -2.733782e+39, "unit": u.Joule, "rtol": 1e-4}, 
+       "log.final.star.LostAngMom": {"value": 8.913482e+40, "unit": (u.kg * u.m ** 2) / u.sec, "rtol": 1e-4}, 
+       "log.final.star.EscapeVelocity": {"value": 6.364062e+05, "unit": u.m / u.sec, "rtol": 1e-4}, 
+       "log.final.star.Luminosity": {"value": 0.036921, "unit": u.LSUN, "rtol": 1e-4}, 
+       "log.final.star.LXUVStellar": {"value": 1.959178e-06, "unit": u.LSUN, "rtol": 1e-4}, 
+       "log.final.star.Temperature": {"value": 3689.002929, "unit": u.K, "rtol": 1e-4}, 
+       "log.final.star.LXUVFrac": {"value": 5.306436e-05, "rtol": 1e-4}, 
+       "log.final.star.RossbyNumber": {"value": 0.669712, "rtol": 1e-4}, 
+       "log.final.star.DRotPerDtStellar": {"value": 2.418466e-12, "rtol": 1e-4}, 
+       "log.final.star.WindTorque": {"value": 3.753272e+22, "rtol": 1e-4}, 
+   } 
+)
+class Test_EngleAutoEarly(Benchmark): 
+   pass 
diff --git a/tests/Stellar/EngleAutoEarly/vpl.in b/tests/Stellar/EngleAutoEarly/vpl.in
@@ -0,0 +1,20 @@
+sSystemName   star
+iVerbose      0
+bOverwrite    1
+
+saBodyFiles   star.in
+
+sUnitMass      solar
+sUnitLength    AU
+sUnitTime      YEARS
+sUnitAngle     d
+
+bDoLog         1
+iDigits        6
+dMinValue      1e-10
+
+bDoForward    1
+bVarDt        1
+dEta          0.01
+dStopTime     1e10
+dOutputTime   1e9
diff --git a/tests/Stellar/EngleAutoMidLate/star.in b/tests/Stellar/EngleAutoMidLate/star.in
@@ -0,0 +1,31 @@
+# Engle24Auto XUV model — MidLate dispatch test.
+# Same physical setup as tests/Stellar/EngleXUV (M=0.181, P_rot=-122d) but
+# with sXUVModel = Engle24Auto.  Because M < 0.40 Msun, Auto-mode dispatch
+# must select the MidLate coefficient set; numerical results should be
+# bit-identical to the EngleXUV benchmark.  Engle24Early coefficients are
+# also present (required by Auto mode) but should not influence the result.
+
+sName               star
+saModules           stellar
+
+dMass               0.181
+dRotPeriod          -122
+dAge                1e9
+
+sStellarModel       baraffe
+sXUVModel           Engle24Auto
+sMagBrakingModel    reiners
+
+# Engle (2024) Early coefficients (unused for M=0.181 < 0.4)
+dXUVEngleEarlyA     -0.4896
+dXUVEngleEarlyB     -3.2128
+dXUVEngleEarlyC     -0.4469
+dXUVEngleEarlyD     -0.2985
+
+# Engle (2024) MidLate coefficients (active for M=0.181 < 0.4)
+dXUVEngleMidLateA   -0.1456
+dXUVEngleMidLateB   -2.8876
+dXUVEngleMidLateC   -1.8187
+dXUVEngleMidLateD    0.3545
+
+saOutputOrder Time -Luminosity -LXUVStellar -LXUVTot
diff --git a/tests/Stellar/EngleAutoMidLate/test_EngleAutoMidLate.py b/tests/Stellar/EngleAutoMidLate/test_EngleAutoMidLate.py
@@ -0,0 +1,78 @@
+from benchmark import Benchmark, benchmark 
+import astropy.units as u 
+
+@benchmark( 
+   { 
+       "log.initial.system.Age": {"value": 3.155760e+16, "unit": u.sec}, 
+       "log.initial.system.Time": {"value": 0.000000, "unit": u.sec}, 
+       "log.initial.system.TotAngMom": {"value": 8.694238e+38, "unit": (u.kg * u.m ** 2) / u.sec}, 
+       "log.initial.system.TotEnergy": {"value": -3.754922e+40, "unit": u.Joule}, 
+       "log.initial.system.PotEnergy": {"value": -3.754922e+40, "unit": u.Joule}, 
+       "log.initial.system.KinEnergy": {"value": 2.591241e+32, "unit": u.Joule}, 
+       "log.initial.system.DeltaTime": {"value": 0.000000, "unit": u.sec}, 
+       "log.initial.star.Mass": {"value": 3.599033e+29, "unit": u.kg}, 
+       "log.initial.star.Radius": {"value": 1.381422e+08, "unit": u.m}, 
+       "log.initial.star.RadGyra": {"value": 0.460833}, 
+       "log.initial.star.RotAngMom": {"value": 8.694238e+38, "unit": (u.kg * u.m ** 2) / u.sec}, 
+       "log.initial.star.RotVel": {"value": 82.344140, "unit": u.m / u.sec}, 
+       "log.initial.star.BodyType": {"value": 0.000000}, 
+       "log.initial.star.RotRate": {"value": 5.960824e-07, "unit": 1 / u.sec}, 
+       "log.initial.star.RotPer": {"value": 1.054080e+07, "unit": u.sec}, 
+       "log.initial.star.Density": {"value": 3.259252e+04, "unit": u.kg / u.m ** 3}, 
+       "log.initial.star.HZLimitDryRunaway": {"value": 8.356400e+09, "unit": u.m}, 
+       "log.initial.star.HZLimRecVenus": {"value": 7.485986e+09, "unit": u.m}, 
+       "log.initial.star.HZLimRunaway": {"value": 9.873134e+09, "unit": u.m}, 
+       "log.initial.star.HZLimMoistGreenhouse": {"value": 9.905190e+09, "unit": u.m}, 
+       "log.initial.star.HZLimMaxGreenhouse": {"value": 1.882335e+10, "unit": u.m}, 
+       "log.initial.star.HZLimEarlyMars": {"value": 2.052890e+10, "unit": u.m}, 
+       "log.initial.star.Instellation": {"value": -1.000000, "unit": u.kg / u.sec ** 3}, 
+       "log.initial.star.CriticalSemiMajorAxis": {"value": -1.000000, "unit": u.m}, 
+       "log.initial.star.LXUVTot": {"value": 4.906221e-06, "unit": u.LSUN}, 
+       "log.initial.star.LostEnergy": {"value": 5.562685e-309, "unit": u.Joule}, 
+       "log.initial.star.LostAngMom": {"value": 5.562685e-309, "unit": (u.kg * u.m ** 2) / u.sec}, 
+       "log.initial.star.EscapeVelocity": {"value": 5.897214e+05, "unit": u.m / u.sec}, 
+       "log.initial.star.Luminosity": {"value": 0.003787, "unit": u.LSUN}, 
+       "log.initial.star.LXUVStellar": {"value": 4.906221e-06, "unit": u.LSUN}, 
+       "log.initial.star.Temperature": {"value": 3212.579977, "unit": u.K}, 
+       "log.initial.star.LXUVFrac": {"value": 0.001295}, 
+       "log.initial.star.RossbyNumber": {"value": 2.012152}, 
+       "log.initial.star.DRotPerDtStellar": {"value": 5.277006e-12}, 
+       "log.initial.star.WindTorque": {"value": 4.352568e+20}, 
+       "log.final.system.Age": {"value": 3.108426e+17, "unit": u.sec, "rtol": 1e-4}, 
+       "log.final.system.Time": {"value": 2.792850e+17, "unit": u.sec, "rtol": 1e-4}, 
+       "log.final.system.TotAngMom": {"value": 8.931191e+38, "unit": (u.kg * u.m ** 2) / u.sec, "rtol": 1e-4}, 
+       "log.final.system.TotEnergy": {"value": -3.698928e+40, "unit": u.Joule, "rtol": 1e-4}, 
+       "log.final.system.PotEnergy": {"value": -3.674712e+40, "unit": u.Joule, "rtol": 1e-4}, 
+       "log.final.system.KinEnergy": {"value": 2.108611e+32, "unit": u.Joule, "rtol": 1e-4}, 
+       "log.final.star.Mass": {"value": 3.599033e+29, "unit": u.kg, "rtol": 1e-4}, 
+       "log.final.star.Radius": {"value": 1.411575e+08, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.RadGyra": {"value": 0.460733, "rtol": 1e-4}, 
+       "log.final.star.RotAngMom": {"value": 8.012348e+38, "unit": (u.kg * u.m ** 2) / u.sec, "rtol": 1e-4}, 
+       "log.final.star.RotVel": {"value": 74.296896, "unit": u.m / u.sec, "rtol": 1e-4}, 
+       "log.final.star.BodyType": {"value": 0.000000, "rtol": 1e-4}, 
+       "log.final.star.RotRate": {"value": 5.263403e-07, "unit": 1 / u.sec, "rtol": 1e-4}, 
+       "log.final.star.RotPer": {"value": 1.193750e+07, "unit": u.sec, "rtol": 1e-4}, 
+       "log.final.star.Density": {"value": 3.054816e+04, "unit": u.kg / u.m ** 3, "rtol": 1e-4}, 
+       "log.final.star.HZLimitDryRunaway": {"value": 8.540511e+09, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimRecVenus": {"value": 7.649893e+09, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimRunaway": {"value": 1.008994e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimMoistGreenhouse": {"value": 1.012207e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimMaxGreenhouse": {"value": 1.923039e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.HZLimEarlyMars": {"value": 2.097284e+10, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.Instellation": {"value": -1.000000, "unit": u.kg / u.sec ** 3, "rtol": 1e-4}, 
+       "log.final.star.CriticalSemiMajorAxis": {"value": -1.000000, "unit": u.m, "rtol": 1e-4}, 
+       "log.final.star.LXUVTot": {"value": 2.529287e-07, "unit": u.LSUN, "rtol": 1e-4}, 
+       "log.final.star.LostEnergy": {"value": -2.421681e+38, "unit": u.Joule, "rtol": 1e-4}, 
+       "log.final.star.LostAngMom": {"value": 9.188425e+37, "unit": (u.kg * u.m ** 2) / u.sec, "rtol": 1e-4}, 
+       "log.final.star.EscapeVelocity": {"value": 5.833888e+05, "unit": u.m / u.sec, "rtol": 1e-4}, 
+       "log.final.star.Luminosity": {"value": 0.003956, "unit": u.LSUN, "rtol": 1e-4}, 
+       "log.final.star.LXUVStellar": {"value": 2.529287e-07, "unit": u.LSUN, "rtol": 1e-4}, 
+       "log.final.star.Temperature": {"value": 3219.534123, "unit": u.K, "rtol": 1e-4}, 
+       "log.final.star.LXUVFrac": {"value": 6.393251e-05, "rtol": 1e-4}, 
+       "log.final.star.RossbyNumber": {"value": 2.286901, "rtol": 1e-4}, 
+       "log.final.star.DRotPerDtStellar": {"value": 3.905842e-12, "rtol": 1e-4}, 
+       "log.final.star.WindTorque": {"value": 2.621569e+20, "rtol": 1e-4}, 
+   } 
+)
+class Test_EngleAutoMidLate(Benchmark): 
+   pass 
diff --git a/tests/Stellar/EngleAutoMidLate/vpl.in b/tests/Stellar/EngleAutoMidLate/vpl.in
@@ -0,0 +1,20 @@
+sSystemName   star
+iVerbose      0
+bOverwrite    1
+
+saBodyFiles   star.in
+
+sUnitMass      solar
+sUnitLength    AU
+sUnitTime      YEARS
+sUnitAngle     d
+
+bDoLog         1
+iDigits        6
+dMinValue      1e-10
+
+bDoForward    1
+bVarDt        1
+dEta          0.01
+dStopTime     1e10
+dOutputTime   1e9