NIRCam (Near-InfraRed Camera) is an instrument aboard the James Webb Space Telescope. It has two major tasks, as an imager from 0.6 to 5 μm wavelength, and as a wavefront sensor to keep the 18-section mirrors functioning as one.[1][2] In other words, it is a camera and is also used to provide information to align the 18 segments of the primary mirror.[3] It is an infrared camera with ten mercury-cadmium-telluride (HgCdTe) detector arrays, and each array has an array of 2048×2048 pixels.[1][2] The camera has a field of view of 2.2×2.2 arcminutes with an angular resolution of 0.07 arcseconds at 2 μm.[1] NIRCam is also equipped with coronagraphs, which helps to collect data on exoplanets near stars. It helps with imaging anything next to a much brighter object, because the coronagraph blocks that light.[2]
NIRCam is housed in the Integrated Science Instrument Module (ISIM), to which it is attached by struts.[3][4][5][6] It is designed to operate at 37 K (−236.2 °C; −393.1 °F), so it can detect infrared radiation at this wavelength.[3][7] It is connected to the ISIM by struts and thermal straps connect to heat radiators, which helps maintain its temperature.[3] The Focal Plane Electronics operated at 290 K.[3]
NIRCam should be able to observe objects as faint as magnitude +29 with a 10,000-second exposure (about 2.8 hours).[8] It makes these observations in light from 0.6 to 5 μm (600 to 5000 nm) wavelength.[4] It can observe in two fields of view, and either side can do imaging, or from the capabilities of the wave-front sensing equipment, spectroscopy.[9] The wavefront sensing is much finer than the thickness of an average human hair.[10] It must perform at an accuracy of at least 93 nanometers and in testing it has even achieved between 32 and 52 nm.[10] A human hair is thousands of nanometers across.[10]