GUIDE STAR Meaning and
Definition
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A guide star is a term commonly used in astronomy to refer to a bright reference star that is used to assist in the accurate alignment and tracking of telescopes or other astronomical instruments. These guide stars serve as stable reference points for astronomers to calibrate their instruments and correct for any distortions or aberrations that may occur during observations.
In the field of adaptive optics, guide stars are crucial. Adaptive optics is a technique used to correct the blurring effect caused by the Earth's atmosphere, which can distort the images captured by telescopes. By focusing on a guide star, astronomers can analyze and measure the atmospheric distortions, and then adjust the shape of a deformable mirror in the telescope to compensate for these distortions in real-time, resulting in much sharper images.
Guide stars are often selected based on their brightness and stability. Most commonly, astronomers use stars that are larger and brighter than average, which makes them more visible and easier to track accurately. However, the choice of a guide star also depends on various factors such as its location in the sky, its distance from the target object, and its availability at a particular time of observation.
In summary, a guide star acts as a reliable reference point for astronomers to align and guide telescopes, correct for atmospheric distortions, and obtain clearer and more accurate observations of celestial objects.
Etymology of GUIDE STAR
The term "guide star" is composed of two words: "guide" and "star".
The word "guide" comes from the Old English word "ganian", meaning "to direct or lead". It has its roots in the Germanic language, ultimately derived from the Proto-Indo-European base *ghedh-, which means "to unite, join, or fit".
The word "star" originates from the Old English word "steorra", which can be traced back to the Proto-Germanic word *sternō. This term is related to the Old Saxon and Old High German word "sterno", the Old Norse word "stjarna", and the Gothic word "stairno". All these words are believed to have originated from the Proto-Indo-European base *ster-, meaning "star".
