In return for the provision of the NIRSpec spectrograph, the European Space Agency (ESA) has received an allocation of 900 hours of JWST guaranteed time (wall-clock time including direct and indirect overheads). This program is managed by the ESA JWST project scientist and is being prepared by the NIRSpec guaranteed-time observer (GTO) team.

On this site, you will find a brief description of each element of the NIRSpec GTO program.

The NIRSpec GTO program is built around one large core program focused on the theme of galaxy formation and evolution, and a set of 5 small and 2 medium programs covering a much wider range of astrophysical topics. Although scientific excellence has been the primary criterion when designing this GTO program, we have also made sure that in the course of these observations, the NIRSpec GTO team will probe the key modes and observation strategies / regimes of the NIRSpec instrument, with the aim to provide early feedback on the data quality and processing steps to the scientific operation center (STScI) and to the community. 

When possible and scientifically valuable, we are planning to obtain NIRCam images in parallel to our NIRSpec multi-object spectroscopy (MOS) exposures.

Note that for GO proposals, coordinated parallels with NIRSpec multi-object spectroscopy and MIRI imaging is also possible.

For the list of supported coordinated parallel instrument combinations, see the JDOX page here.