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Calibrator Star
A calibrator star is a star that is typically used for calibration purposes on high-sensitized sensors located on space telescopes. Calibrator stars do not usually follow a specific criteria, but are normally hand-picked for different reasons. Definition Infrared and optically bright stars may be observed for calibration purposes by satellites, particularly those with sensitivity to both infrared and visible radiation. The stars chosen generally meet the following criteria: they have a visual magnitude that is equal to or less than +6, and an IR brightness (in the 1-5 micrometer range) greater than that of Vega. The stars are strictly southern objects (i.e., their declinations are negative), and most are cool stars of spectral classes K and M. While these are not the only stars that might serve for these purposes, they are well distributed across the southern sky and some should be visible at all times. List Catalog A catalog of recommended calibrator stars does exist, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JWST Telescope Alignment Evaluation Image Labeled
The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, List of the most distant astronomical objects, distant, or faint for the Hubble Space Telescope. This enables investigations across many fields of astronomy and cosmology, such as observation of the Population III star, first stars and the Galaxy formation and evolution, formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets. Although the Webb's mirror diameter is 2.7 times larger than that of the Hubble Space Telescope, it produces images of comparable optical resolution, resolution because it observes in the longer-wavelength infrared spectrum. The longer the wavelength of the spectrum, the larger the information-gathering surface required (mirrors in the infrared spectrum or antenna a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transiting Exoplanet Survey Satellite
Transiting Exoplanet Survey Satellite (TESS) is a space telescope for NASA's Explorer program, designed to search for exoplanets using the transit method in an area 400 times larger than that covered by the Kepler mission. It was launched on 18 April 2018, atop a Falcon 9 launch vehicle and was placed into a highly elliptical 13.70-day orbit around the Earth. The first light image from TESS was taken on 7 August 2018, and released publicly on 17 September 2018. In the two-year primary mission, TESS was expected to detect about 1,250 transiting exoplanets orbiting the targeted stars, and an additional 13,000 orbiting stars not targeted but observed. After the end of the primary mission around 4 July 2020, scientists continued to search its data for more planets, while the extended missions acquires additional data. , TESS had identified 7,643 candidate exoplanets, of which 627 had been confirmed. The primary mission objective for TESS was to survey the brightest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Spectroscopy
Astronomical spectroscopy is the study of astronomy using the techniques of spectroscopy to measure the electromagnetic spectrum, spectrum of electromagnetic radiation, including Visible light astronomy, visible light, Ultraviolet astronomy, ultraviolet, X-ray astronomy, X-ray, Infrared astronomy, infrared and Radio astronomy, radio waves that radiant energy, radiate from stars and other celestial objects. A stellar spectrum can reveal many properties of stars, such as their chemical composition, temperature, density, mass, distance and luminosity. Spectroscopy can show the velocity of motion towards or away from the observer by measuring the Doppler effect, Doppler shift. Spectroscopy is also used to study the physical properties of many other types of celestial objects such as planets, nebulae, Galaxy, galaxies, and Active galactic nucleus, active galactic nuclei. Background Astronomical spectroscopy is used to measure three major bands of radiation in the electromagnetic spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stars
A star is a luminous spheroid of plasma held together by self-gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night; their immense distances from Earth make them appear as fixed points of light. The most prominent stars have been categorised into constellations and asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye—all within the Milky Way galaxy. A star's life begins with the gravitational collapse of a gaseous nebula of material largely comprising hydrogen, helium, and traces of heavier elements. Its stellar mass, total mass mainly determines its stellar evolution, evolution and eventual fate. A star shines for main sequence, most of its active life due to the thermonu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Light (astronomy)
In astronomy, first light is the first use of a telescope (or, in general, a new instrument) to take an astronomical image after it has been constructed. This is often not the first viewing using the telescope; optical tests will probably have been performed to adjust the components. Characteristics The first light image is normally of little scientific interest and is of poor quality, since the various telescope elements are yet to be adjusted for optimum efficiency. Despite this, a first light is always a moment of great excitement, both for the people who design and build the telescope and for the astronomical community, who may have anticipated the moment for many years while the telescope was under construction. A well-known and spectacular astronomical object An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical entity, association, or structure that exists within the observable universe. In astronomy, the te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lists Of Stars
The following are lists of stars. Stars are astronomical objects that spend some portion of their existence generating energy through thermonuclear fusion. By location * Lists of stars by constellation By name * List of proper names of stars * List of Arabic star names * Chinese star names * Nakshatra * Stars named after people By distance * List of most distant stars Nearest stars * List of nearest stars (up to 20 light-years) * List of nearest stars by spectral type * List of nearest bright stars * List of nearest giant stars * List of nearest supergiants 20–100 light years away * List of star systems within 20–25 light-years * List of star systems within 25–30 light-years * List of star systems within 30–35 light-years * List of star systems within 35–40 light-years * List of star systems within 40–45 light-years * List of star systems within 45–50 light-years * List of star systems within 50–55 light-years * List of star systems within 55–60 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Webb Space Telescope
The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, List of the most distant astronomical objects, distant, or faint for the Hubble Space Telescope. This enables investigations across many fields of astronomy and cosmology, such as observation of the Population III star, first stars and the Galaxy formation and evolution, formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets. Although the Webb's mirror diameter is 2.7 times larger than that of the Hubble Space Telescope, it produces images of comparable optical resolution, resolution because it observes in the longer-wavelength infrared spectrum. The longer the wavelength of the spectrum, the larger the information-gathering surface required (mirrors in the infrared spectrum or antenna a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Webb's First Image Of Focused Star (potm2203a)
Webb's a.k.a. H. S. Webb, was a department store based in Glendale, California, the first in that city. Origins The store was founded by Harry S. Webb (d. 1947) in 1917 in Downtown Glendale in a single room. It had locations in the Glendale Fashion Center and in Redlands, California. Ned Blanc purchased the store from Webb in 1949 but kept the name. In 1951 Blanc expanded the original store at 139 N. Brand into the adjacent Lawson Building. There was a fire at the store in 1977. Webb's moved to a former J. C. Penney store about half the size of Webb's original store, on the southeast corner of Brand Blvd. and California Avenue. Glendale Fashion Center Two years later, it moved to the Glendale Fashion Center in a space vacated by Joseph Magnin when that store moved to the Glendale Galleria. Webb's expanded the space from 30,000 to 67,500 square feet and moved into it on September 27, 1979. Decline For half a century, Webb's was the only major department store in Glendale. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vega
Vega is the brightest star in the northern constellation of Lyra. It has the Bayer designation α Lyrae, which is Latinised to Alpha Lyrae and abbreviated Alpha Lyr or α Lyr. This star is relatively close at only from the Sun, and one of the most luminous stars in the Sun's neighborhood. It is the fifth-brightest star in the night sky, and the second-brightest star in the northern celestial hemisphere, after Arcturus. Vega has been extensively studied by astronomers, leading it to be termed "arguably the next most important star in the sky after the Sun". Vega was the northern pole star around 12,000 BCE and will be so again around the year 13,727, when its declination will be . Vega was the first star other than the Sun to have its image and spectrum photographed. It was one of the first stars whose distance was estimated through parallax measurements. Vega has functioned as the baseline for calibrating the photometric brightness scale and was one of the stars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R Doradus
R Doradus (HD 29712 or P Doradus) is a red giant variable star in the far-southern constellation Dorado, close to the border with Reticulum. Its distance from Earth is . Having a angular diameter, uniform disk diameter of , it is thought to be the extrasolar star with the largest apparent size as viewed from Earth. Variability The visible magnitude of R Doradus varies between 4.8 and 6.3, which means it is usually visible to the naked eye, but in the infrared light, infrared it is one of the brightest stars in the sky. With a near-infrared J band (infrared), J band Magnitude (astronomy), magnitude of −2.65, only Betelgeuse and Antares at −2.9 and −2.73 (respectively) are brighter. In the infrared K band (infrared), K band, it is sometimes the brightest star in the sky, although usually Betelgeuse is brighter. It is classified as a semiregular variable star of type SRb, indicating giants with slow poorly-defined variations, often alternating between periodic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler Space Telescope
The Kepler space telescope is a defunct space telescope launched by NASA in 2009 to discover Earth-sized planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched into an Earth-trailing heliocentric orbit. The principal investigator was William J. Borucki. After nine and a half years of operation, the telescope's reaction control system fuel was depleted, and NASA announced its retirement on October 30, 2018. Designed to survey a portion of Earth's region of the Milky Way to discover Earth-size exoplanets in or near habitable zones and to estimate how many of the billions of stars in the Milky Way have such planets, Kepler's sole scientific instrument is a photometer that continually monitored the brightness of approximately 150,000 main sequence stars in a fixed field of view. These data were transmitted to Earth, then analyzed to detect periodic dimming caused by exoplanets that cross in front of their host star. Only planets whos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
