The James Webb Space Telescope Mission: Optical Telescope Element Design, Development, and Performance

Abstract

The James Webb Space Telescope (JWST) is a large, infrared space telescope that has recently started its science program which will enable breakthroughs in astrophysics and planetary science. Notably, JWST will provide the very first observations of the earliest luminous objects in the universe and start a new era of exoplanet atmospheric characterization. This transformative science is enabled by a 6.6 m telescope that is passively cooled with a 5 layer sunshield. The primary mirror is comprised of 18 controllable, low areal density hexagonal segments, that were aligned and phased relative to each other in orbit using innovative image-based wave front sensing and control algorithms. This revolutionary telescope took more than two decades to develop with a widely distributed team across engineering disciplines. We present an overview of the telescope requirements, architecture, development, superb on-orbit performance, and lessons learned. JWST successfully demonstrates a segmented aperture space telescope and establishes a path to building even larger space telescopes.

JWST-TST Proper Motions. I. High-precision NIRISS Calibration and Large Magellanic Cloud Kinematics

“…The P2SF of JWST appears to be relatively stable over the available temporal baseline, with deviations below ∼5% except for the F090W and F150W ERS data, for which we measured respective central-pixel variations of about ∼7% and 6%. This appears to be consistent with the stability of the Optical Telescope Element of JWST discussed in McElwain et al (2023). Temporal variations appear to be less prominent in redder filters.…”

“…This is the first in a series of papers by our JWST Telescope Scientist Team to extend the astrometric legacy and lessons learned from HST to JWST. The JWST observatory is uniquely suited for this, due to its high image quality and temporal stability (McElwain et al 2023). This offers several exciting new future opportunities, including: (a) the ability to study much fainter objects, owing to the large mirror size of JWST compared to HST, which in turn yields better statistics and accuracy in measurements of the mean and dispersion in kinematic properties, while also enabling PM studies of more distant objects; (b) the ability to conduct PM studies of regions that are too extincted for HST or Gaia, thanks to JWSTʼs infrared sensitivity; and (c) the ability to extend the time baseline of imagery with space-based resolution to an era when HST may no longer be available.…”

“…Commissioning observations. While many potentially contributing factors were changing during Commissioning, there were no commanded adjustments in telescope mirror alignment or instrument focus (McElwain et al 2023) over the time period of these measurements, and further, the observatory had already reached thermal stabilization weeks earlier, such that there were no substantial ongoing thermal drifts (Menzel et al 2023, PASP in press). We also computed the scale against the HST-based reference frame (Anderson et al 2021), against a pure Gaia DR3 frame (for the reddest filter that has more stars with G < 19 in common with the Gaia catalog), and against the central-pointing NIRISS image, and in all cases saw a similar trend.…”

JWST UNCOVER: Extremely Red and Compact Object at z phot ≃ 7.6 Triply Imaged by A2744

“…Moreover, while the quasar luminosity function (LF) implies a larger abundance of fainter objects (i.e., faint end slopes of ∼1.2-1.6; e.g., Glikman et al 2011;Niida et al 2020) similar to the galaxy LF, faint quasars with M UV  −22 seem to be rare in observations. Indeed, the JWST (Gardner et al 2006;McElwain et al 2023), launched one year ago, may help in finding more such objects. Recent work suggests that active galactic nuclei (AGNs) that are excessively massive relative to their host galaxies, accreting at high Eddington rates, would be detectable with JWST at high redshifts (Volonteri et al 2023) and potentially shed light on early black hole growth.…”

JWST's TEMPLATES for Star Formation: The First Resolved Gas-phase Metallicity Maps of Dust-obscured Star-forming Galaxies at z ∼ 4

“…The launch of JWST and its successful commissioning (Rigby et al 2023a(Rigby et al , 2023bGardner et al 2023;McElwain et al 2023;Menzel et al 2023) have transformed our ability to study galaxy formation and evolution, and we are now entering a new era for extragalactic astronomy. JWSTʼs Near-Infrared Spectrograph (NIRSpec; Böker et al 2023) can study highredshift galaxies at sub-kpc spatial resolution, offering a vast improvement over previous ground-based (and therefore seeing-limited) studies.…”