The mirror has a polished area of 26.3 m 2 (283 sq ft), of which 0.9 m 2 (9.7 sq ft) is obscured by the secondary support struts, giving a total collecting area of 25.4 m 2 (273 sq ft). Webb has a 6.5 m (21 ft)-diameter gold-coated beryllium primary mirror made up of 18 separate hexagonal mirrors. The mass of the James Webb Space Telescope is about half that of the Hubble Space Telescope. A major redesign was accomplished in 2005, with construction completed in 2016, followed by years of exhaustive testing, at a total cost of US$10 billion. The program was plagued with enormous cost overruns and delays. Two concept studies were commissioned in 1999, for a potential launch in 2007 and a US$1 billion budget. Initial designs for the telescope, then named the Next Generation Space Telescope, began in 1996. Its five-layer sunshield protects it from warming by the Sun, Earth, and Moon. The telescope must be kept extremely cold, below 50 K (−223 ☌ −370 ☏), so that the infrared light emitted by the telescope itself does not interfere with the collected light. Unlike Hubble, which observes in the near ultraviolet and visible (0.1 to 0.8 μm), and near infrared (0.8–2.5 μm) spectra, Webb observes a lower frequency range, from long-wavelength visible light (red) through mid-infrared (0.6–28.3 μm). This gives Webb a light-collecting area of about 25 square meters, about six times that of Hubble. Webb's primary mirror consists of 18 hexagonal mirror segments made of gold-plated beryllium, which together create a 6.5-meter-diameter (21 ft) mirror, compared with Hubble's 2.4 m (7 ft 10 in). Webb, who was the administrator of NASA from 1961 to 1968 during the Mercury, Gemini, and Apollo programs. The primary contractor for the project was Northrop Grumman. The NASA Goddard Space Flight Center (GSFC) in Maryland managed telescope development, while the Space Telescope Science Institute in Baltimore on the Homewood Campus of Johns Hopkins University operates Webb. National Aeronautics and Space Administration (NASA) led Webb's design and development and partnered with two main agencies: the European Space Agency (ESA) and the Canadian Space Agency (CSA). The telescope's first image was released to the public on 11 July 2022. In January 2022 it arrived at its destination, a solar orbit near the Sun–Earth L 2 Lagrange point, about 1.5 million kilometers (930,000 mi) from Earth. The Webb was launched on 25 December 2021 on an Ariane 5 rocket from Kourou, French Guiana. This enables investigations across many fields of astronomy and cosmology, such as observation of the first stars and the formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets. Its high-resolution and high-sensitivity instruments allow it to view objects too old, distant, or faint for the Hubble Space Telescope. "Simulations of gravitationally lensed galaxies like this help us reconstruct how much mass is in individual stars, along with how much dark matter is in the core of this galaxy.The James Webb Space Telescope ( JWST) is a space telescope designed to conduct infrared astronomy. "These images of the lensed galaxy are so faint and so red that they went unrecognized in Hubble data, but are unmistakable in Webb's near-infrared image," Windhorst said in the statement. The galaxy shines as a small, dim dot at 4 o'clock in the zoomed-in inset. The second apparition, however, is much harder to spot. In fact, the lensed galaxy is visible twice in this image, thanks to the duplicating effect that comes with gravitational lensing. The unknown galaxy, which has not yet been named, can be seen on the left of the white elliptical galaxy as an arced streak of orange light. (Image credit: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe (University of Melbourne), JWST PEARLS Team) Astronomers discovered a previously unknown galaxy thanks to the combination of James Webb Space Telescope's infrared vision and the effect known as gravitational lensing.
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