MuSCAT2: four-color simultaneous camera for the 1.52-m Telescopio Carlos Sánchez

We report the development of a four-color simultaneous camera for the 1.52-m Telescopio Carlos Sánchez in the Teide Observatory, Canaries, Spain. The instrument, named MuSCAT2, has a capability of four-color simultaneous imaging in g (400 to 550 nm), r (550 to 700 nm), i (700 to 820 nm), and z_s (820 to 920 nm) bands. MuSCAT2 equips four 1024 × 1024 pixel CCDs, having a field of view of 7.4 × 7.4 arc min² with a pixel scale of 0.44 arc sec per pixel. The principal purpose of MuSCAT2 is to perform high-precision multicolor exoplanet transit photometry. We demonstrate photometric precisions of 0.057%, 0.050%, 0.060%, and 0.076% as root-mean-square residuals of 60 s binning in g, r, i, and z_s bands, respectively, for a G0 V star WASP-12 (V = 11.57 ± 0.16). MuSCAT2 has started science operations since January 2018, with over 250 telescope nights per year. MuSCAT2 is expected to become a reference tool for exoplanet transit observations and substantially contributes to the follow-up of the Transiting Exoplanet Survey Satellite and Planetary Transits and Oscillations of stars space missions.