Fourier fits to the photometric data of the asteroid (121514) 1999 UJ7. Different colours correspond to data from different nights. Left panel: light curve with fitted third-order Fourier polynomial in red (top panel) andthe residuals (bottom panel) using data from 1, 2, 5, and 6 Dec 2016. The obtained period is 1.936 ± 0.002 d. Middle panel: as for the left panel, but fitting data from 29 Dec 2016 and 01 Jan 2017. The obtained period in this case is 1.848 ± 0.028 d. Right panel: as in middle panel, but keeping the period fixed at P = 1.936 d.