Table 2: Derived parameters of the envelope model for various star masses.

From: Blue large-amplitude pulsators as a new class of variable stars

M/M log Teff log L/L log g Mcore/M rcore/R ηF η1O Model
0.30 4.4886 2.2572 4.5496 0.2983 0.1061 −0.239 −0.473 Shell H-burning
0.35 4.4886 2.3039 4.5710 0.3474 0.1161 −0.230 −0.417  
0.40 4.4886 2.3440 4.5901 0.3963 0.1255 −0.225 −0.380  
0.45 4.4886 2.3787 4.6073 0.4450 0.1343 −0.223 −0.354  
0.50 4.4886 2.4097 4.6229 0.4934 0.1427 −0.222 −0.334  
0.60 4.4886 2.4626 4.6500 0.5893 0.1582 −0.224 −0.306  
0.80 4.4886 2.5466 4.6926 0.7777 0.1852 −0.234 −0.275  
1.00 4.4886 2.6123 4.7250 0.9613 0.2083 −0.247 −0.261 Core He-burning
1.20 4.4886 2.6659 4.7509 1.1399 0.2286 −0.258 −0.254  
  1. The bottom of the envelope is placed at the radius r = rcore where temperature is 2 × 107 K. Normalized driving rate η is calculated for the fundamental mode (F) and first overtone (1O). The two versions of evolutionary models consistent with similar values of L(Mcore) are given in the last column. Heavy 1.0M helium cores are formed in the evolution of stars with MZAMS ≈ 5M. In this case, a huge mass loss is required to create a BLAP. A much lower mass loss is needed if the BLAPs are shell hydrogen-burning objects with degenerate helium cores. At M = 0.3M, the core has similar mass and luminosity to a MZAMS ≈ 1M star on the red giant branch well before helium flash.