SIRUS: a near infrared simultaneous three-band camera

We developed a near infrared simultaneous three-band (J, H and Ks) camera, SIRIUS. The design of SIRIUS is optimized to deep, large area surveys in the three IR bands. SIRIUS is equipped with three 1024 x 1024 HgCdTe (HAWAII) arrays, providing simultaneous three-band images. SIRIUS has obtained its first light on the UH 2.2 m telescope in August 2000. SIRIUS is now mounted on the IRSF 1.4 m telescope in Sutherland and is dedicated to deep survey in the southern sky from November 2000. On this telescope, SIRIUS provides 7'.8 x 7'.8 field of view with a pixel scale of 0".45 in all bands. The typical limiting magnitudes are J = 19.2 mag, H = 18.6 mag, Ks = 17.3 mag (15 min. integration, S/N = 10 σ). The effective exposure time (30 sec exposure for each frame) in an hour is about 37 minutes (60%) for each band. Both the instrument and the 1.4 m telescope are in operation.