Light curve of Apophis taken from February 7.0, 2021, to March 16.2, 2021 reduced to the unit geocentric and heliocentric distance and to a consistent solar phase angle. The blue open circles indicate the photometric data folded with P₁. The red curves denote the best-fit fourth-order two-period Fourier series with the periods P₁ = 30.56 h and P₂ = 27.38 h. The black squares indicate the residuals of the photometric data from the fourth-order two-period Fourier series (see the right ordinates).