Initial stellar evolution for t < t₀. Panel a: accretion history of the star. Initially, the star accretes with a constant accretion rate, Ṁ_init. At time t_dec, the accretion rate drops according to Ṁ_⋆ ∝ t⁻² (see text). The colored dashed lines show the respective value of Ṁ_start. Panel b: evolution of the stellar mass. Starting from the initial mass of 0.01 M_⊙, all models reach their final mass of 0.91 M_⊙ after 2 Myr. The yellow, red, and blue lines show models with Ṁ_start = [1 × 10⁻⁹, 5 × 10⁻⁹, and 1 × 10⁻⁸] M_⊙ yr⁻¹, respectively. To show the entire initial stellar evolution, starting from t = 0 yr, we use the symlog representation (Hunter 2007). The vertical dashed line indicates the transition from the linear scale (for t ≤ 10⁴ yr) to the logarithmic scale (for t > 10⁴ yr).