141 research outputs found
The James Webb Space Telescope
The James Webb Space Telescope (JWST) is a large, infrared-optimized space telescope. JWST's primary science goal is to detect and characterize the first galaxies. It will also study the assembly of galaxies, star formation, and the formation of evolution of planetary systems. The observatory has a large primary mirror 6.5 meter in diameter, designed to deliver high angular resolution in the infrared, combined with a large collecting area. The telescope optics are designed and fabricated to operate at the cryogenic temperatures (,...,40 k) required for an IR optimized telescope. The primary mirror is also a segmented mirror architecture. The observatory is designed to achieve cryogenic operating temperature via passive cooling, facilitated by a five-layer sunshield which keeps the telescope in the sun's shadow. Since the observatory dimensions exceed the Ariane 5 fairing size, the observatory has to be stowed for launch and deployed following launch. The observatory will be launched into an L2 orbit that provides continuous science operations and a benign thermal environment for optical stability
Overview of the James Webb Space Telescope Observatory
The James Webb Space Telescope (JWST) is a cryogenic, 6.5 meter diameter space telescope. JWST has a unique architecture, compared to previous space telescopes, that is driven by its science requirements, ia passively cooled cryogenic design, and the need to stow the observatory for launch. JWST's large, segmented mirror meets the requirement for high angular resolution in the infrared coupled with a significant increase in collecting area compared to the Spitzer and Hubble Space telescopes in order to detect the first galaxies. JWST's unique five-layer sunshield allows the telescope and instrument module to passively cool to cryogenic temperatures. JWST will be launched on an Ariane 5, and so both its telescope optics, and the sunshield have to be stowed in order to fit the Ariane 5 fairing. Following launch the sunshield and telescope optics must be deployed, and the primary mirror phased for science operations. In this presentation we will review the design of the observatory and highlight recent progress in the construction of the JWST observatory. In particular, we address recent progress with the telescope optics, sunshield and spacecraft. We will discuss predicted observatory performance in terms of the scientific goals of JWST and address key operational considerations that might bear upon frontier science observations
The James Webb Space Telescope and its Capability for for Exoplanet Observations
The James Webb Space Telescope (JWST) is a large aperture (6.5 .meter), cryogenic space telescope with a suite of near and mid-infrared instruments covering the wavelength range of 0.6 micron to 28 micron. JWST's primary science goal is to detect and characterize the first galaxies. It will also study the assembly of galaxies, star formation, and the formation of evolution of planetary systems. In this presentation we will discuss the status of the JWST project and review the expected scientific performance of the observatory for observations of exosolar planets by means of transit observations, and direct coronagraphic imaging. In particular we will discuss recent simulations of photometric and spectroscopic transit observations that demonstrate the capabilities of JWST to characterize superearth atmospheres in the light of recent Kepler and Corot discoverie
The James Webb Space Telescope: Capabilities for Exoplanet Science
The James Webb Space Telescope (JWST) is a large aperture (6.5 meter), cryogenic space telescope with a suite of near and mid-infrared instruments covering the wavelength range of 0.6 micron to 28 micron. JWST's primary science goal is to detect and characterize the first galaxies. It will also study the assembly of galaxies, stellar and planetary system formation, and the formation and evolution of planetary systems. We will review the design of JWST, and discuss the current status of the project, with emphasis on recent progress in the construction of the observatory. We also review the capabilities of the observatory for observations of exosolar planets and debris disks by means of coronagraphic imaging, and high contrast imaging and spectroscopy. This discussion will focus on the optical and thermal performance of the observatory, and will include the current predictions for the performance of the observatory, with special reference to the demands of exoplanet science observations
Observing New Worlds with Space Telescopes
The search for exoplanets and characterization of their properties has seen increasing success over the last few years. In excess of 500 explanets are known and there are approximately 1200 additional candidates. Recently, progress has been made in direct imaging planets, both from the ground and in space. This presentation will discuss the history and current state of technology used for such discoveries, and highlight the new results enabled by the current and future space telescopes
Exploring Extrasolar Planetary Systems: New Observations of Extrasolar Planets Enabled by the James Webb Space Telescope
The search for extrasolar planets has been increasingly success over the last few years. In excess of 700 systems are now known, and Kepler has approx.2500 additional candidate systems, yet to be confirmed. Recently, progress has also been made in directly imaging extrasolar planets, both from the ground and in space. In this presentation will discuss the techniques employed to discover planetary systems, and highlight the capabilities, enabled by the James Webb Space Telescope (JWST). JWST is a large 6.5 meter aperture infrared telescope that is scheduled for launch in 2018, and will allow us to transition to characterizing the properties of these extrasolar planets and the planetary systems in which they reside
Observing Exoplanets with the James Webb Space Telescope
The search for exoplanets and characterization of their properties has seen increasing success over the last few years. In excess of 500 exoplanets are known and Kepler has approx. 1000 additional candidates. Recently, progress has been made in direct imaging planets, both from the ground and in space. This presentation will discuss the history and current state of technology used for such discoveries, and highlight the new capabilities that will be enabled by the James Webb Space Telescope
Space Telescopes
Space telescopes have been a dominant force in astrophysics and astronomy over the last two decades. As Lyman Spitzer predicted in 1946, space telescopes have opened up much of the electromagnetic spectrum to astronomers, and provided the opportunity to exploit the optical performance of telescopes uncompromised by the turbulent atmosphere. This special section of Optical Engineering is devoted to space telescopes. It focuses on the design and implementation of major space observatories from the gamma-ray to far-infrared, and highlights the scientific and technical breakthroughs enabled by these telescopes. The papers accepted for publication include reviews of major space telescopes spanning the last two decades, in-depth discussions of the design considerations for visible and x-ray telescopes, and papers discussing concepts and technical challenges for future space telescopes
STIS Coronagraphic Imaging of Fomalhaut: Main Belt Structure and the Orbit of Fomalhaut b
We present new optical coronagraphic data of the bright star Fomalhaut
obtained with the HST in 2010/2012 using STIS. Fomalhaut b is recovered at both
epochs to high significance. The observations include the discoveries of
tenuous nebulosity beyond the main dust belt detected to at least 209 AU
projected radius and a ~50 AU wide azimuthal gap in the belt northward of Fom
b. The morphology of Fomalhaut b appears elliptical in the STIS detections. We
show that residual noise in the processed data can plausibly result in point
sources appearing extended. A MCMC analysis demonstrates that the orbit of Fom
b is highly eccentric, with e=0.8+/-0.1, a=177+/-68 AU, and q = 32+/-24 AU. Fom
b is apsidally aligned with the belt and 90% of allowed orbits have mutual
inclination 36 deg or less. Fomalhaut b's orbit is belt-crossing in projection,
but only 12% of possible orbits have nodes within a 25 AU wide belt annulus
(133-158 AU). The high e invokes a dynamical history where Fom b may have
experienced a significant dynamical interaction with a hypothetical planet
Fomalhaut c, and the current orbital configuration may be relatively
short-lived. The new value for the periastron distance diminishes the Hill
radius of Fom b and any weakly bound satellite system surrounding a planet
would be sheared and dynamically heated at periapse. We argue that Fom b's
minimum mass is that of a dwarf planet in order for a circumplanetary satellite
system to remain bound to a sufficient radius from the planet to be consistent
with the dust scattered light hypothesis. Fom b may be optically bright because
the recent passage through periapse and/or the ascending node has increased the
erosion rates of planetary satellites. In the coplanar case, Fomalhaut b will
collide with the main belt around 2032, and the subsequent emergent phenomena
may help determine its physical nature.Comment: 49 Pages, 33 Figures, 5 Tables; Submitted to ApJ, Dec. 31, 201
Space Telescope Sensitivity and Controls for Exoplanet Imaging
Herein we address design considerations and outline requirements for space telescopes with capabilities for high contrast imaging of exoplanets. The approach taken is to identify the span of potentially detectable Earth-sized terrestrial planets in the habitable zone of the nearest stars within 30 parsecs and estimate their inner working angles, flux ratios, SNR, sensitivities, wavefront error requirements and sensing and control times parametrically versus aperture size. We consider 1, 2, 4, 8 and 16-meter diameter telescope apertures. The achievable science, range of telescope architectures, and the coronagraphic approach are all active areas of research and are all subject to change in a rapidly evolving field. Thus, presented is a snapshot of our current understanding with the goal of limiting the choices to those that appear currently technically feasible. We describe the top-level metrics of inner working angle, contrast and photometric throughput and explore how they are related to the range of target stars. A critical point is that for each telescope architecture and coronagraphic choice the telescope stability requirements have differing impacts on the design for open versus closed-loop sensing and control
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