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

The angle between the operating facet of the grooves and the overall plane of a diffraction grating.

→ blaze; → angle.

Angâl, zâviyée, → angle; beliz→ blaze.

The wavelength in a given diffraction order for which the efficiency curve reaches its maximum.

→ blaze; → wavelength.

Mowjtul→ wavelength; beliz→ blaze.

A → diffraction grating ruled appropriately so that a large proportion of the diffracted light is concentrated into a few, or even a single → order of interference.

Blazed, adj. of → blaze; → grating.

Turi, noun from tur "a net, a fishing net;" belizi adj. from beliz, → blaze.

A long term, generally irregular modulation of → light curves of a large subclass of → RR Lyrae stars. Most of the modulations occur on the time scale of some 60 periods, although the range extends from some tens to some hundreds of periods. Since its discovery over a hundred years ago, a number of explanations have been proposed for this effect, but its nature is still a matter of investigation. The explanations include: closely spaced pulsation modes, a modal 1 : 2 resonance, an oblique rotator model, a non-radial modal interaction, convective cycles, and nonlinear resonant mode coupling between the 9th overtone and the fundamental mode (see, e.g., R. Buchler and Z. Kolláth 2011, astro-ph/1101.1502).

Named after Sergei N. Blazhko (1870-1956), a Russian astronomer who discovered the effect for the star EW Dra (1907, Astron. Nachr. 175, 325); → effect.

A star showing the → Blazhko effect.

→ Blazhko effect; → star.

The capcity of a diffraction grating, in certain configurations, to concentrate a large percentage of the incident light into a specific diffraction order.

Blazing, noun from → blaze.

Belizeš, noun from beliz "blaze."

General: A flaw or defect.
Detectors: Latent imperfections in the photodiodes (pixels) of a solid-state detector.

From O.Fr. blemiss "to turn pale," extended stem of blemir, blesmir "to injure, make pale."

Âk "defect, blemish," Mid.Pers. ak, âk "evil, harm," Av. aka- "bad, wicked;" cf. Skt. aka- "pain , trouble."

1a) Description of two or more adjacent → spectral lines which are mixed due to insufficient → resolving power of the → spectrograph.
1b) Linguistics: A word which is coined by extracting and combining arbitrary pieces of two or more existing words. Examples include → smog, motel (motor + hotel), brunch (breakfast + lunch), → pulsar, and → shellular. Same as portmanteau.
2) Of two or more → spectral lines, to become merged into one line as a consequence of insufficient instrumental → resolution.

M.E., from O.N. blanda; akin to O.E. blandan "to mix," Lith. blandus "impure, cloudy."

Tuham, from tu "inside" + ham "together," → com-.

→ Spectral lines intermingled.

→ blend; → line.

Unable to see; sightless.

M.E., from O.E. blind "blind," akin to Du., Ger. blind, O.N. blindr, Goth. blinds "blind."

Kur "blind," variants kul "squint-eyed," kolok, kalek, kelek, kalâž, kâž, kâj, kâc "squint-eyed," Lori, Laki, Kurd. xêl "cross-eyed, squinting;" Mid.Pers. kôr "blind;" akin to O.Irish coll "one-eyed;" M.Irish goll "blind;" Gk. (Hes.) kellas "one-eyed;" Skt. kāná- "blind of one eye;" PIE *kolnos "one-eyed." The Pers. luc "crossed-eyed" may be related to a separate group containing L. lusca, luscus "one-eyed" (Fr. louche "squinting").

The state or condition of being sightless.

→ blind; → -ness.

1) To close and open the eyes rapidly.
2) To shine intermittently; flash on and off.

M.E. blinken, variant of blenken "to blench;" cf. Du. and Ger. blinken.

Možidan, from možé "eyelash," Mid.Pers. mec "eyelash," mecitan "to blink," cf. Skt. mes "to open the eyes," O.C.S. po-mežiti "to close the eyes." → twinkling.

An instrument for comparing two photographs of the same stellar field, taken at different times, by quickly alternating from one to the other. The purpose of the comparison is to detect subtle changes in the position or brightness of the stars.

→ blink; → comparator.

Hamsanjgar, → comparator; možeš noun from možidan, → blink.

An intermittent appearance of a group of characters on the display terminal, usually used to convey a message to the user.

Blinking, noun from to blink.

Možeš, noun from možidan, → blink (v).

A small cyst on the skin, containing watery liquid, as from a burn or other injury.

M.E. blister, blester, from O.Fr. blestre, of Germanic origin.

Tâval "blister" (variants Torbet-Heydariye-yi toval, Guqari tavol), from suffixed (-al) tâv- tav, taf- "to heat, burn, shine," variant of tâb-, tâbidan "to shine," → luminous.

A model according to which an → H II region is a hot mass of ionized gas located on the surface of a → molecular cloud, like a blister on the body skin.

→ blister; → model.

A new type of astronomical object, appearing as an intense → burst of → radio emission, proposed to explain → fast radio bursts. In some models, blitzars result from the sudden → collapse of a hypothetical → supermassive neutron star.

From Ger. Blitz, "→ flash, lightening," + -âr ending component, as in → pulsar.

A severe weather condition characterized by high winds (at least 55 km/h) and reduced visibility due to violent snowstorm.

Blizzard, of unknown origin.

Damé "wind and snow storm."

1) General: Drop of liquid; small round mass (e.g. wax); spot of color.
2) Astro.: A relatively → small, → unresolved source lying toward a much larger structure. → high-excitation blob.

From M.E. bubelen "to bubble."

Žig "drop," probably from žohidan "to drop," variant of cakidan "to drop."

The red liquid that circulates in the arteries and veins of humans and other vertebrate animals, carrying oxygen to and carbon dioxide from the tissues of the body (OxfordDictionaries.com).

M.E. blo(o)d, O.E. blôd; akin to O.Frisian, O.Saxon blôd, O.H.G. bluot (Ger. Blut), Gothic bloth.

Xun, from Mid.Pers. xûn; cf. Sogd. xurn, Khotanese hûna, Yaghnobi waxin, Av. vohunī,