PARSEC V2.0 - Pure-He stellar tracks

In this database can be found Pure-He stellar evolutionary tracks. All details on the physical assumptions, and on the evolutionary properties of the tracks can be find in Costa, Shepherd et al. 2025.

Stellar evolutionary tracks

The grids of pure-He stellar tracks contains models computed with an initial mass that ranges from 0.36 M⊙\odot to 350 M⊙\odot, in the metallicity range between Z=1E-6 and Z=0.05. The total dataset contains more than ~1200 tracks. All stellar tracks have been computed with PARSEC v2.0, details can be find in the paper cited above.

The tables for each stellar track contains the quantities listed in the following table

Column number Quantity Description
1 MASS Current total mass [M⊙\odot]
2 AGE Age [yr]
3 Dtime Time-step of the previous model [yr]
4 LOG_L log10 total luminosity [log10 L⊙\odot]
5 LOG_TE Effective temperature [log10 K]
6 RSTAR Star radius [cm]
7 CONV Mass of the convective core (incl. overshooting) [M/Mtot]
8 QSCHW Mass of the unstable core (Schwartzschild criterion, w/o overshooting) [M/Mtot]
9 QHEL Mass of the He-core, i.e. where X < 10-3 [M/Mtot]
10 QCAROX Mass of the Carbon Oxygen (CO) core, i.e. where Y = 10-3 [M/Mtot]
11 LOG_Tc log10 central temperature [log10 K]
12 LOG_RHc log10 central density [log10 g cm-3]
13 LOG_Pc log10 central pressure [log10 10-1 Pa]
14 PSI_C Degeneracy parameter in the center
15 G1_AVG Averaged Γ\Gamma1 adiabatic index (through the whole star)
16 XCEN Central H1 mass fraction
17 XHE3C Central He3 mass fraction
18 YCEN Central He4 mass fraction
19 XC_CEN Central C12 mass fraction
20 XN_CEN Central N14 mass fraction
21 XO_CEN Central O16 mass fraction
22 XNE_CEN Central Ne20+Ne22 mass fraction
23 XMG_CEN Central Mg24+Mg25+Mg26 mass fraction
24 XSI28_CEN Central Si28 mass fraction
25 RATE Mass loss or accretion rate [M⊙\odot yr-1]
26 Xsup Surface H1 mass fraction
27 Ysup Surface He4 mass fraction
28 XCsup Surface C12 mass fraction
29 XC13sup Surface C13 mass fraction
30 XNsup Surface N14 mass fraction
31 XOsup Surface O16 mass fraction
32 XO18sup Surface O18 mass fraction
33 XNEsup Surface Ne20 + Ne22 mass fraction
34 XMGsup Surface Mg24 + Mg25 + Mg26 mass fraction
35 POLRAD_ENV Star polar radius [cm]
36 EQRAD_ENV Star equatorial radius [cm]
37 OMG_ENV Angular rotation rate = angular velocity / angular critical velocity
38 ANG_VEL_ENV envelope angular velocity [cm s-1]
39 TANVEL_ENV tangential linear velocity at the equator [cm s-1]
40 TOT_INERTIA Total moment of inertia of the star [g cm2]
41 TOT_ANGMOM Total angular momentum [g cm2 s-1]
42 TOT_MOM_LOST Total angular momentum lost due to stellar wind [g cm2 s-1]
43 R_CONV Radius at CONV [log10 cm]
44 RHEL Radius at QHEL [log10 cm]
45 R_CAROX Radius at QCAROX [log10 cm]
46 INERTIA_HEL He-core inertia [log10 g cm2]
47 ANGMOM_HEL He-core angular momentum [log10 g cm2 s-1]
48 INERTIA_CAROX CO-core inertia [log10 g cm2]
49 ANGMOM_CAROX CO-core angular momentum [log10 g cm2 s-1]
50 TMAX Maximum temperature [log10 K]
51 RHTMAX Density where T = TMAX [log10 g cm-3]
52 QTMAX Mass coordinate where T = TMAX [M/Mtot]
53 LNUC Luminosity produced by nuclear burning [L/Ltot]
54 LX Luminosity by hydrogen burning [L/Ltot]
55 LY Luminosity by helium burning [L/Ltot]
56 LC Luminosity by carbon burning [L/Ltot]
57 LNEUTR Neutrinos luminosity [L/Ltot]
58 L_GRAV Gravitational luminosity [L/Ltot]
59 L_ACC Accretion luminosity [L/Ltot]
60 Q_CNV Mass coordinate depth of convective envelope [M/Mtot]
61 DPTH_CNV Radial depth of convective envelope [log10 cm]
62 INERTIA_CNV Inertia of the convective envelope [log10 g cm2]
63 ANGMOM_CNV Angular momentum of the convective envelope [log10 g cm2 s-1]
64 TCNV_YR Turnover timescale of convective bubble [yr]
65 T20L10 Atmosphere temperature of the gas at τ\tau = 20 [log10 K]
66 RH20L10 Atmosphere density of the gas at τ\tau = 20 [log10 g cm-3]
67 P20L10 Atmosphere pressure of the gas at τ\tau = 20 [log10 10-1 Pa]
68 TE20L10 Effective temperature at τ\tau = 20 [log10 K]
69 R20L10 Atmosphere radius at τ\tau = 20 [log10 cm]
70 MU20 Atmosphere molecular weight at τ\tau = 20 [log10 cm]
71 T2_3L10 Atmosphere temperature of the gas at τ\tau = 2/3 [log10 K]
72 RH2_3L10 Atmosphere density of the gas at τ\tau = 2/3 [log10 g cm-3]
73 P2_3L10 Atmosphere pressure of the gas at τ\tau = 2/3 [log10 10-1 Pa]
74 TE2_3L10 temperature from Stefan-Boltzmann law at τ\tau = 2/3 [log10 K]
75 R2_3L10 Atmosphere radius at τ\tau = 2/3 [log10 cm]
76 MU2_3 Atmosphere molecular weight at τ\tau = 2/3 [log10 cm]