Optical to NIR light curves of WR 122

We present optical and infrared (IR) light curves of NaSt1, also known as Wolf-Rayet 122, with observations from Palomar Gattini-IR (PGIR), the Zwicky Transient Facility (ZTF), the Katzman Automatic Imaging Telescope, the Asteroid Terrestrial-impact Last Alert System, and the All-Sky Automated Survey for Supernovae (ASAS-SN). We identify a P=309.7+/-0.7day photometric period from the optical and IR light curves that reveal periodic, sinusoidal variability between 2014 July and 2021 July.

We also present historical IR light curves taken between 1983 July and 1989 May, which show variability consistent with the period of the present-day light curves. In the past, NaSt1 was brighter in the J band with larger variability amplitudes than the present-day PGIR values, suggesting that NaSt1 exhibits variability on longer (>~decade) timescales. Sinusoidal fits to the recent optical and IR light curves show that the amplitude of NaSt1's variability differs at various wavelengths and also reveal significant phase offsets of 17.0+/-2.5day between the ZTF r and PGIR J light curves.