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STARLIB: Thermonuclear Rate Library


Starlib is a library of thermonuclear reaction and laboratory weak interaction rates. It can be used for studies of stellar models and nucleosynthesis. Starlib lists in three columns, for about 50,000 nuclear interactions, the stellar temperature (in GK), the thermonuclear reaction rate (in cm^3 s^-1 mol^-1) or decay rate (in s^-1), and the uncertainty factor of the rate. The library was first introduced in the paper by Sallaska et al. (2013).

The rates and uncertainty factors are listed on a temperature grid from 0.001 GK to 10.0 GK. Starlib incorporates about 70 experimental thermonuclear reaction rates that have been estimated using Monte Carlo methods. These methods were first introduced in papers by Longland et al. (2010) and Iliadis et al. (2016). Starlib has the unique feature of providing, at each temperature grid point, the probability density of the total reaction rate. This feature is important for realistic nucleosynthesis simulations, and has been discussed in the review paper by Iliadis et al. (2015). The latest version of the library is available for download.

The project was initially funded by the National Science Foundation under Award Number AST-1008355. At present, it is funded by NASA under the Astrophysics Theory Program grant 14-ATP14-0007 and by the U.S. Department of Energy under grant number DE-FG02-97ER41041.


For each nuclear interaction contained in Starlib, the first line has a fixed format. It contains (i) the interaction type (see below) as an integer value in fields (1:2); (ii) the interacting nuclides before and after the interaction, where each nuclide label is right aligned in a field of size five; (iii) the rate reference label (see below) in fields (45:48); (iv) the interaction character in field 49, where “v”, “w”, and “g” stand for “reverse reaction”, “laboratory weak inetraction”, and “gamma-ray transition”, respectively; (v) the energy released (+) or consumed (-) in the interaction in fields (54:65).

For each interaction contained in Starlib, the following lines list the reaction rates on a 60-value temperature grid from 0.001 GK to 10 GK.

Experimental rates that are not estimated using the Monte Carlo approach are incorporated into Starlib in the following manner: (i) the recommended rate as calculated from the reported low and high rates (left-hand side of Eq. (39) in Longland et al. (2010); (ii) the factor uncertainty is calculated from the reported low and high rates (right-hand side of Eq. (39) in Longland et al. (2010); thus it is explicitly assumed that these rates are lognormally distributed.

Interaction type

The integer value between 1 and 11 in fields (1:2) denotes the following interaction types:

  1. e1 –> e2
  2. e1 –> e2 + e3
  3. e1 –> e2 + e3 + e4
  4. e1 + e2 –> e3
  5. e1 + e2 –> e3 + e4
  6. e1 + e2 –> e3 + e4 + e5
  7. e1 + e2 –> e3 + e4 + e5 + e6
  8. e1 + e2 + e3 –> e4
  9. e1 + e2 + e3 –> e4 + e5
  10. e1 + e2 + e3 + e4 –> e5 + e6
  11. e1 –> e2 + e3 + e4 + e5

Rate reference labels

Reaction rates based on experiment:

Reaction rates based on Hauser-Feshbach models:

Weak laboratory decay rates based on experiment:

Weak laboratory decay rates based on theory:

Weak stellar decay rates based on theory:

Gamma-ray decay rates (for excited 26Al levels only):

Individual rates:


C. Iliadis, K.S. Anderson, A. Coc, F.X. Timmes, and S. Starrfield, Bayesian Estimation of Thermonuclear Reaction Rates, Astrophys. J. 831, 107 (2016).

C. Iliadis, R. Longland, A. Coc, F.X. Timmes, and A.E. Champagne, Statistical Methods for Thermonuclear Reaction Rates and Nucleosynthesis Simulations, J. Phys. G 42, 034007 (2015).

R. Longland, C. Iliadis, A.E. Champagne, J.R. Newton, C. Ugalde, A. Coc, and R. Fitzgerald, Charged-Particle Thermonuclear Reaction Rates: I. Monte Carlo Method and Statistical Distributions, Nucl. Phys. A, 841, 1 (2010).

A.L. Sallaska, C. Iliadis, A.E. Champagne, S. Goriely, S. Starrfield, and F.X. Timmes, Starlib: A Next-Generation Reaction-Rate Library for Nuclear Astrophysics, Astrophys. J. Suppl. 207, 18 (2013).


The current version is Starlib_v6.5_090617.