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Goddard High Resolution Spectrograph
The Goddard High Resolution Spectrograph (GHRS or HRS) was an ultraviolet spectrograph installed on the Hubble Space Telescope during its original construction, and it was launched into space as part of that space telescope aboard the Space Shuttle '' Discovery'' on April 24, 1990 ( STS-31). The instrument is named after 20th century rocket pioneer Robert H. Goddard. One of the results was the discovery of tenuous atmosphere for Jupiter's moon Europa in 1995. The gas was determined to be mostly of molecular oxygen (O2). The surface pressure of Europa's atmosphere is 0.1 μPa, or 10−12 times that of the Earth. An example GHRS use was to observe the local interstellar medium in the direction towards Capella. The Goddard High Resolution Spectrograph was removed from the Hubble Space Telescope during the February, 1997, Space Shuttle ''Discovery'' mission STS-82 (also called SM-2 for Servicing Mission 2). It, and the Faint Object Spectrograph, were replaced by two new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capella
Capella is the brightest star in the northern constellation of Auriga. It has the Bayer designation α Aurigae, which is Latinised to Alpha Aurigae and abbreviated Alpha Aur or α Aur. Capella is the sixth-brightest star in the night sky, and the third-brightest in the northern celestial hemisphere after Arcturus and Vega. A prominent object in the northern winter sky, it is circumpolar to observers north of 44°N. Its name meaning "little goat" in Latin, Capella depicted the goat Amalthea that suckled Zeus in classical mythology. Capella is relatively close, at from the Sun. It is one of the brightest X-ray sources in the sky, thought to come primarily from the corona of Capella Aa. Although it appears to be a single star to the naked eye, Capella is actually a quadruple star system organized in two binary pairs, made up of the stars Capella Aa, Capella Ab, Capella H and Capella L. The primary pair, Capella Aa and Capella Ab, are two bright-yellow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope Instruments
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Resolution
The spectral resolution of a spectrograph, or, more generally, of a frequency spectrum, is a measure of its ability to resolve features in the electromagnetic spectrum. It is usually denoted by \Delta\lambda, and is closely related to the resolving power of the spectrograph, defined as R = \frac, where \Delta\lambda is the smallest difference in wavelengths that can be distinguished at a wavelength of \lambda. For example, the Space Telescope Imaging Spectrograph (STIS) can distinguish features 0.17 nm apart at a wavelength of 1000 nm, giving it a resolution of 0.17 nm and a resolving power of about 5,900. An example of a high resolution spectrograph is the ''Cryogenic High-Resolution IR Echelle Spectrograph'' (CRIRES+) installed at ESO's Very Large Telescope, which has a spectral resolving power of up to 100,000. Doppler effect The spectral resolution can also be expressed in terms of physical quantities, such as velocity; then it describes the difference between ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanometer
330px, Different lengths as in respect to the molecular scale. The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American and British English spelling differences#-re, -er, American spelling) is a units of measurement, unit of length in the International System of Units (SI), equal to one billionth ( short scale) of a metre () and to 1000 picometres. One nanometre can be expressed in scientific notation as , and as metres. History The nanometre was formerly known as the millimicrometre – or, more commonly, the millimicron for short – since it is of a micron (micrometre), and was often denoted by the symbol mμ or (more rarely and confusingly, since it logically should refer to a ''millionth'' of a micron) as μμ. Etymology The name combines the SI prefix '' nano-'' (from the Ancient Greek , ', "dwarf") with the parent unit name ''metre'' (from Greek , ', "unit of measuremen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angstrom
The angstromEntry "angstrom" in the Oxford online dictionary. Retrieved on 2019-03-02 from https://en.oxforddictionaries.com/definition/angstrom.Entry "angstrom" in the Merriam-Webster online dictionary. Retrieved on 2019-03-02 from https://www.merriam-webster.com/dictionary/angstrom. (, ; , ) or ångström is a metric unit of length equal to m; that is, one ten-billionth ( US) of a metre, a hundred-millionth of a centimetre,Entry "angstrom" in the Oxford English Dictionary, 2nd edition (1986). Retrieved on 2021-11-22 from https://www.oed.com/oed2/00008552. 0.1 nanometre, or 100 picometres. Its symbol is Å, a letter of the Swedish alphabet. The unit is named after the Swedish physicist Anders Jonas Ångström (1814–1874). The angstrom is often used in the natural sciences and technology to express sizes of atoms, molecules, microscopic biological structures, and lengths of chemical bonds, arrangement of atoms in crystals,Arturas Vailionis (2015):Geometry of Crystals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wavelength
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The inverse of the wavelength is called the spatial frequency. Wavelength is commonly designated by the Greek letter '' lambda'' (λ). The term ''wavelength'' is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids. Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. Wavelength depends on the medium (for example, vacuum, air, or water) that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Telescope Imaging Spectrograph
The Space Telescope Imaging Spectrograph (STIS) is a spectrograph, also with a camera mode, installed on the Hubble Space Telescope. Aerospace engineer Bruce Woodgate of the Goddard Space Flight Center was the principal investigator and creator of the STIS. It operated continuously from 1997 until a power supply failure in August 2004. After repairs, it began operating again in 2009. The spectrograph has made many important observations, including the first spectrum of the atmosphere of an extrasolar planet, HD 209458b. The STIS was installed on Hubble in 1997 during its second servicing mission ( STS-82) by Mark Lee and Steven Smith, replacing the High Resolution Spectrograph and the Faint Object Spectrograph. It was designed to operate for five years. On August 3, 2004, an electronic failure rendered STIS inoperable, ending its use 2 years beyond its predicted lifespan. In order to bring it back to operational status, the instrument was repaired by space shuttle astro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near Infrared Camera And Multi-Object Spectrometer
The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is a scientific instrument for infrared astronomy, installed on the Hubble Space Telescope (HST), operating from 1997 to 1999, and from 2002 to 2008. Images produced by NICMOS contain data from the near-infrared part of the light spectrum. NICMOS was conceived and designed by the NICMOS Instrument Definition Team centered at Steward Observatory, University of Arizona, USA. NICMOS is an imager and spectrometer built by Ball Aerospace & Technologies Corp. that allows the HST to observe infrared light, with wavelengths between 0.8 and 2.4 micrometers, providing imaging and slitless spectrophotometric capabilities. NICMOS contains three near-infrared detectors in three optical channels providing high (~ 0.1 arcsecond) resolution, coronagraphic and polarimetric imaging, and slitless spectroscopy in 11-, 19-, and 52-arcsecond square fields of view. Each optical channel contains a 256×256 pixel photodiode array of merc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Faint Object Spectrograph
The Faint Object Spectrograph (FOS) was a spectrograph installed on the Hubble Space Telescope. It was replaced by the Space Telescope Imaging Spectrograph The Space Telescope Imaging Spectrograph (STIS) is a spectrograph, also with a camera mode, installed on the Hubble Space Telescope. Aerospace engineer Bruce Woodgate of the Goddard Space Flight Center was the principal investigator and creato ... in 1997, and is now on display in the National Air and Space Museum in Washington DC. FOS facts *Instrument type: Spectrograph *Wavelength range: 115 to 850 nm A technical description of the construction and operation of the FOS can be found in NASA technical report CP-2244., page 55. A 40 MB PDF file. The instrument used two digicon detectors, 'blue' and 'red', and had a spectral resolution of about 1300 over the 115 nm to 850 nm range. It had a number of apertures of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STS-82
STS-82 was the 22nd flight of the Space Shuttle ''Discovery'' and the 82nd mission of the Space Shuttle program. It was NASA's second mission to service the Hubble Space Telescope, during which ''Discovery's'' crew repaired and upgraded the telescope's scientific instruments, increasing its research capabilities. ''Discovery'' launched from Kennedy Space Center, Florida, on 11 February 1997, returning to Earth on 21 February 1997 at Kennedy Space Center. Crew Spacewalks *''EVA 1'' Lee and Smith **Start: 14 February 1997 – 04:34 UTC **End: 14 February 1997 – 11:16 UTC **Duration: 6 hours, 42 minutes *''EVA 2'' Harbaugh and Tanner **Start: 15 February 1997 – 03:25 UTC **End: 15 February 1997 – 10:52 UTC **Duration: 7 hours, 27 minutes *''EVA 3'' Lee and Smith **Start: 16 February 1997 – 02:53 UTC **End: 16 February 1997 – 10:04 UTC **Duration: 7 hours, 11 minutes *''EVA 4'' Harbaugh and Tanner **Start: 17 February 1997 – 03:45 UTC **End: 17 February 1997 – 10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
