Upper panel: the optical-to-X-ray spectral energy distribution of the afterglow of GRB 100219A is shown in the upper panel. The X-ray point corresponds to 1 keV. The values of β_OX relative to the I-band (unaffected by the Lyα blanketing) and R-band (affected by the Lyα blanketing) are 0.56 (t = 34 ks) and 0.41 (t = 35 ks), marked with a solid line and a dash-dotted line, respectively. The Galactic correction E(B − V) = 0.08 is used. Lower panel: fitting of the late X-ray spectrum with a broken power-law. The time interval is between 5.0 ×  10³ s and 1.8 × 10⁵ s.