Hebrew English

מצפה הכוכבים ברקת - קוד מצפה רשמי Bareket observatory IAU B35

לחיפוש במונחון הזן טקסט ולחץ חפש

Glossaries

מנוח הסבר המונח
Celestial pole

The north and south celestial poles are points on the celestial sphere where earths axis of rotation intersects the celestial sphere.

Cepheid

A pulsating variable star, undergoes a rhythmic pulsation as indicated by its regular pattern of changing brightness as a function of time. The period of pulsation has been demonstrated to be directly related to a Cepheid's intrinsic brightness.

Comet

Chunk of frozen gasses, ice, and rocky debris that orbits the Sun. As the nucleus begins to disintegrate, it also produces a dust tail in its orbital path and a gas or ion tail pointing away from the Sun.

Computer Hand Control
מחשב הטלסקופ – שלט המאפשר שליטה ובחירת מטרות הצפייה
Constellation

A grouping of stars that make an imaginary characters in the sky. There are 88 constellations.

Cosmic Ray

Atomic nuclei (mostly protons) which observed to strike the Earth's atmosphere with extremely high amounts of energy. Cosmic Rays sometimes hit the telescope's CCD camera which may leave a trails on the final image.

Eclipse

The total or partial blocking of one celestial body by another

Emission line

A bright line in a spectrum caused by emission of light. Each chemical element emits and absorbs radiated energy at specific wavelengths. The collection of emission lines in a spectrum corresponds to the chemical elements contained in a celestial object.

Ephemeris

Tables of data which list the positions of the Sun, Moon, planets and other Solar System objects

Escape velocity

The minimum velocity required for an object to escape the gravity of a massive object.

Exposure

The process of allowing electromagnetic radiation to fall on light-sensitive materials such as the camera's CCD detector. An exposure is also the image created by the process. A long exposure time is needed in order to obtain an image of dim and distant celestial objects.

Extrasolar planet

A planet that orbits a star - other than the sun

Eyepiece
עינית
Field of view

The area of the sky visible through a telescope. The telescope’s viewing area is measured in degrees, arc minutes, or arc seconds. Our main telescope that can fit the about half of the full moon into its complete viewing area, so that is has a field of view of roughly 15 arc minutes.

Filter

An optical window that absorbs certain colors of light while allowing others to pass through. Astronomers use filters to observe how celestial objects appear in certain colors (wavelength) of light.

Finderscope
כוונת הטלסקופ, באמצעותה ממקמים את האובייקט באופן גס, טרם הצפייה בטלסקופ.
Focal Length

אורך המוקד של הטלסקופ. ראו הרחבה במאמר לבחירת טלסקופ.

 

Focal Ratio
יחס המוקד של הטלסקופ. ראה הרחבה במאמר לבחירת טלסקופ.
Galaxy

A system of about 100 billion stars. Our Sun is a member of the Milky Way Galaxy. There are billions of galaxies in the observable universe, most of them are to far in order to be seen with the unaided eye. Galaxies are classified in three main groups; spirals, ellipticals and irregulars. The Milky Way galaxy is spiral in shape.

Galaxy cluster

A collection of dozens to thousands of galaxies bound together by gravity

Gas giant

A large planet with a small, rocky core and a deep atmosphere composed mostly of hydrogen and helium. Our solar system contains four gas giants: Jupiter, Saturn, Uranus, and Neptune. This group is also known as Jovian planets.