The first on-sky data using the new NIRCam short wavelength grism time-series capability have recently been obtained. Previously, the grism time-series mode obtained spectroscopy only in the long wavelength channel (2.4 to 5 microns) while the simultaneous short wavelength channel was restricted to time series imaging. With the implementation of the new “multistripe” capability, time-series spectroscopy from 0.6 to 2.3 microns can be taken simultaneously with long wavelength spectroscopy, and it enables observations of targets with K-band magnitudes as bright as −2 to −1 mag. This new capability is available for Cycle 6 proposers. The figure below shows data of a spectral calibration star, with the level-2 pipeline products shown on the top and the extracted spectrum shown on the bottom.

Observers are encouraged to contact the NIRCam team via the JWST Help Desk with any questions.