An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 3 Search : Herschel
Herschel
  هرشل   
Herschel

Fr.: Herschel   

Sir William Herschel (1738-1822), German-born English astronomer, the discoverer of the → infrared radiation and planet → Uranus.
Herschelian telescope, → Herschel Satellite

Herschel Satellite
  ماهواره‌ی ِ هرشل   
mâhvâre-ye Herschel

Fr.: Satellite Herschel   

A European Space Agency (ESA) mission to perform imaging photometry and spectroscopy in the → far infrared and → submillimeter regions of the electromagnetic spectrum, covering approximately the 55-672 µm range. In fact Herschel is the first space facility dedicated to these wavelength ranges. It carries a 3.5 m diameter passively cooled mirror. The science payload complement - two cameras/medium resolution spectrometers (PACS and SPIRE) and a very high resolution → superheterodyne spectrometer (HIFI) - are housed in a superfluid helium cryostat. Herschel was launched on 14 May 2009, together with the → Planck Satellite. Its observing position lies at the L2 → Lagrangian point, some 1.5 million km from Earth. Herschel is designed, among other things, to study the formation of galaxies in the early Universe, and to investigate the formation of stars and their interaction with the → interstellar medium.

Herschel; → satellite.

Herschelian telescope
  تلسکوپ ِ هرشل، دوربین ~   
teleskop-e Herschel, durbin-e ~

Fr.: télescope de Herschel   

A → reflecting telescope in which the → primary mirror is tilted so that light is focused near one side of the open end of the tube. The → eyepiece then picks up this light directly, avoiding light loss from reflection by a → secondary mirror. The drawback is → astigmatism, unless the → focal ratio is large. Herschel used this design in his giant 48-inch instrument.

Herschel; → telescope.