The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope

IV. Capabilities and predicted performance for exoplanet characterization

¹ European Space Agency, Space Telescope Science Institute, Baltimore, Maryland, USA
e-mail: stephan.birkmann@esa.int
² European Space Agency, European Space Astronomy Centre, Madrid, Spain
³ ATG Europe for the European Space Agency, European Space Research and Technology Centre, Noordwijk, The Netherlands
⁴ Department of Physics, University of Oxford, UK
⁵ CEA Saclay, Gif-sur-Yvette, France
⁶ NASA Goddard Space Flight Center, Observational Cosmology Laboratory, Greenbelt, USA
⁷ Space Telescope Science Institute, Baltimore, USA
⁸ Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen, Denmark
⁹ Airbus Defence and Space GmbH, Friedrichshafen, Germany
¹⁰ Centro de Astrobiologia (CSIC-INTA), Departamento de Astrofisica, Madrid, Spain
¹¹ Sorbonne Université, CNRS, UMR 7095, Institut d'Astrophysique de Paris, France
¹² European, Space Agency, European Space Research and Technology Centre, Noordwijk, The Netherlands
¹³ AURA for the European Space Agency, Space Telescope Science Institute, Baltimore, Maryland, USA
¹⁴ Aurora Technology for the European Space Agency, European Space Astronomy Centre, Madrid, Spain
¹⁵ Kavli Institute for Cosmology, University of Cambridge, UK
¹⁶ Quantum Circuits, Inc., New Haven, Connecticut, USA
¹⁷ NRC Herzberg, Victoria, British Columbia, Canada

Received: 5 November 2021
Accepted: 26 January 2022

Abstract

The Near-Inrared Spectrograph (NIRSpec) on the James Webb Space Telescope (JWST) is a very versatile instrument, offering mul-tiobject and integral field spectroscopy with varying spectral resolution (~30 to ~3000) over a wide wavelength range from 0.6 to 5.3 micron, enabling scientists to study many science themes ranging from the first galaxies to bodies in our own Solar System. In addition to its integral field unit and support for multiobject spectroscopy, NIRSpec features several fixed slits and a wide aperture specifically designed to enable high precision time-series and transit as well as eclipse observations of exoplanets. In this paper we present its capabilities regarding time-series observations, in general, and transit and eclipse spectroscopy of exoplanets in particular. Due to JWST’s large collecting area and NIRSpec’s excellent throughput, spectral coverage, and detector performance, this mode will allow scientists to characterize the atmosphere of exoplanets with unprecedented sensitivity.