An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Gaps in → atmospheric absorption, allowing a range of electromagnetic wavelengths to pass through the atmosphere and reach the Earth.

→ atmospheric; → window.

An area of the sky with relatively low amounts of  → interstellar dust along the → line of sight, occurring toward the  → constellation of  → Sagittarius, near the → globular cluster NGC 6522. The window, through which stars in the → Galactic bulge are visible, lies 3.9 degrees south of the → Galactic center, corresponding to a line of sight that passes within 1,800 → light-years of the → Milky Way's core. It is named after Walter Baade, who used it to observe → RR Lyrae stars  in the → Galactic bulge region. 

→ Baade-Wesselink method; → window.

The regions near the Galactic plane where there is low absorption of light by interstellar clouds so that some external galaxies may be seen through them.

→ galactic; → window.

A range of infrared wavelengths to which the Earth's atmosphere is relatively transparent, and at which observations can be made from the ground. Infrared windows are found near wavelengths of 1.25, 1.65, 2.2, 3.6, 5.0, 10, 20, and 30 microns, and beyond 300 microns.

→ infrared; → window.

The optical portion of the electromagnetic spectrum that passes through the atmosphere all the way to the ground.

→ optical; → window.

A range of electromagnetic radiation in the radio frequencies to which the Earth's atmosphere is transparent.

→ radio; → window.

A → window function that is constant inside a specified interval.

→ rectangular; → window.

1) Anything likened to a window in appearance or function.
2) In particular, the wavelength region in the electromagnetic spectrum that is relatively unaffected by atmospheric absorption. → atmospheric windows; → infrared window; → optical window; → radio window.

Window literally "wind eye," from O.N. vindauga, from vindr, → wind, + auga, → eye.

Rowzané, from rowzan "window, aperture;" Mid.Pers. rocânak "window," rôšn "light; bright, luminous," from Av. raocana- "bright, shining, radiant," raocah- "light, luminous; daylight," related to Mod.Pers. ruz "day," from Mid.Pers. rôc, O.Pers. raucah-; akin to Skt. rocaná- "bright, shining," roka- "brightness, light;" Gk. leukos "white, clear;" L. lux "light" (also lumen, luna); PIE base *leuk- "light, brightness." The Persian words rowšan "bright, clear," foruq "light," and afruxtan "to light, kindle" also belong to this family, as well as the E. light, Ger. Licht, and Fr. lumière; forusorx→ infrarouge.

A function whose value is zero outside a given interval. Applications of window functions include signal filtering and spectral analysis. The various types of windw functions include: → rectangular window, cosine window, triangular window, Gaussian window, Hanning window, and so on.

→ window; → function.