396 Chandra X-Ray Observatory

The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space observatory launched on STS-93 by NASA on July 23, 1999. Chandra is sensitive to x-ray sources 100 times fainter than any previous x-ray telescope, enabled by the high angular resolution of its mirrors. Since the Earth’s atmosphere […]

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422 Gran Telescopio Canarias

The Gran Telescopio Canarias (also known as GTC), is an ambitious Spanish project with the aim of constructing and operating one of the largest and most advanced telescopes in the world. With the leadership of the Instituto de Astrofísica de Canarias (IAC), its First Light Ceremony was celebrated in the early morning of 14th July, […]

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424 Karl Guthe Jansky and Radio Waves

Radio astronomy is the study of the radio frequencies emitted from stars, galaxies and other celestial objects. Radio waves are produced naturally from lightning and astronomical objects, or are produced by man-made communication techniques and broadcasting technology. Many radio telescopes are located around the globe and have helped discover new types of stars and galaxies […]

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461 First Reflecting Telescope

English physicist Isaac Newton built the first reflecting telescope in 1668. Newton’s idea for a reflecting telescope was not new. Galileo Galilei and Giovanni Francesco Sagredo had discussed using a mirror as the image forming objective soon after the invention of the refracting telescope, and others, such as Niccolò Zucchi, claimed to have experimented with […]

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462 Aberration of Starlight

By the 18th century, all astronomers believed that Earth revolved around the Sun, and not vice versa, but they had no direct observational proof. English astronomer James Bradley provided confirmation in 1729 when he discovered the aberration of starlight. Essentially, he found that an observer has to point his or her telescope slightly in the […]

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464 200-inch Hale Telescope

  On January 26, 1949, the 200-inch Hale Telescope at Palomar Observatory in California collected its first light from a celestial object—Hubble’s Variable Nebula (NGC 2261). The instrument’s construction had begun in 1934, but interruptions from World War II delayed its completion. The primary optic in the Hale Telescope was the first large mirror made […]

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471 Energy Collected by Radio Telescopes

A radio telescope is a specialized antenna and radio receiver used to receive radio waves from astronomical radio sources in the sky in radio astronomy. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum emitted by astronomical objects, just as optical telescopes are […]

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