Lomb-Scargle periodograms of the COBE/DIRBE satellite 1.25μ flux intensity measurements, the Hipparcos photometric measurements, the H_α EW variations, and the BVS variations for HD 166141 (top to bottom panel). The vertical dashed line marks the location of the period of 480 days and the horizontal dotted lines indicate an FAP threshold of 1 × 10^-3 (0.1%). Top panel – the solid line is the Lomb-Scargle periodogram of the COBE/DIRBE satellite 1.25μ flux intensity measurements for 3.5 years. The arrows show the positions of the dominant peaks at = 0.00390  ±  0.00008 c d^-1 ( = 256.1  ±  5.4 days) and at = 0.00142  ±  0.00008 c d^-1 ( = 703.0  ±  39.4 days). The dashed line shows the periodogram of the residuals after removing of the  day fit from the original data. The dotted line shows the periodogram after removing of the = 703 day fit from the original data.