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

A → lenticular galaxy (S0) in → Hydra constellation located about 130 million → light-years (40 ± 8 Mpc, → redshift z = 0.009680) from Earth, discovered by William Herschel in 1789. On 17 August 2017 the → Laser Interferometer Gravitational-Wave Observatory (LIGO) and the → Virgo Interferometer both detected → gravitational waves (→ GW170817) from the collision of two → neutron stars within this galaxy. The → electromagnetic counterpart GRB 170817A was detected 1.7 seconds later. The event was associated with a → kilonova offset 10.6 arcsec (corresponding to 2.0 kpc) to north-east from the nucleus of NGC 4993.

NGC, → New General Catalog

A → lenticular galaxy in the constellation of the → Draco. It lies about 50 million → light-years (15.3 Mpc) distant and has a size of about 60,000 light-years. Due to its thin → rdge-on appearance, it is also called the → Spindle Galaxy. Known also as Messier 102.

5866, a serial number in the → New General Catalogue.

A → reflection nebula located in the constellation → Cepheus at a distance of 1,300 → light-years. It was discovered by Sir William Herschel on October 18, 1794. The nebula, also known as the → Iris Nebula and → Caldwell 4, is about 6 light-years across. At the center of NGC 7023 lies an extremely young star named V380 Cep or SAO 19158 (mag. +7.1), which is associated with plenty of local dust. NGC 7023 is located 6 degrees northwest of the brightest star in Cepheus, Alderamin (α Cep - mag. +2.5) with third magnitude Alfirk (Beta Cephei) positioned about 3.5 degrees to the northeast. Only a degree east-northeast of NGC 7023 is Mira type variable star T Cep, which fluctuates between magnitudes +5.2 and +11.3 over a period of 388.14 days.

7023, a serial number in the → New General Catalogue.

PIE prefix *ni- "down, below."

E. nether is from this PIE root; M.E. nethere, O.E. neothera, nithera "down, downward, below, beneath" (cf. O.S. nithar, O.N. niðr, O.Fris. nither, Du. neder, Ger. nieder); akin to Pers. ne-, ni-, as below.

Mod.Pers. ne-, ni- "down, below" (as in negâh "look, watch," nešastan "to sit down," nehoftan "to conceal," nehâdan "to place, put," nemudan "to display," nefrin "curse," etc.); Mid.Pers. ni-, O.Pers. preposition and verbal prefix ni- "down;" Av. nī- "down, in, into;" cf. Skt. ni- "down," nitaram "downward;" Gk. neiothen "from below" (from ne-[io]- "below" + -then "from, since;" other usage examples of -then: po-then "from where," paidio-then "since childhood," panta-ho-then "from everywhere."); E. nether, as above.

Metallic chemical element belonging to the iron group; symbol Ni. Atomic number 28; atomic weight 58.69; melting point about 1,453°C; boiling point about 2,732°C. It was discovered by the Swedish metallurgist Axel-Fredrik Cronstedt (1722-1765) in 1751.

Nickel, from shortening of Swedish kopparnickel "copper-colored ore," from which it was first obtained, a half-translation of Ger. Kupfernickel, literally "copper demon," from Kupfer "copper" + Nickel "demon, rascal" (from Nikolaus; cf. E. Old Nick "the devil;" the ore so called by miners because it looked like copper but yielded none.

Optical device constructed from a crystal of calcite, used for obtaining plane polarized light.

Named after John Pringle Nicol (1804-1859), British physicist; → prism.

The period between → sunrise and → sunset, especially the hours of darkness.

M.E., from O.E. niht (O.H.G. naht, Du., Ger. Nacht, O.N. natt, Goth. nahts), from PIE *nok(w)t- "night;" cf. Gk. nuks; L. nox (Fr. nuit; Sp. noche); Skt. nákt-; Av. *naxtar- "night," upa.naxtar- "adjoining the night" (Kurd. Soriani nûtak (?) "sheer darkness"); Lith. naktis; Russ. noch'.

Šab, from Mid.Pers. šab, šap "night;" O.Pers. xšap- "night;" Av. xšapan-, xšafn-, xšap- "night;" cf. Skt. ksáp- "night;" PIE base *k(w)sep- "night."

A specialized technician in an observatory who is in charge of functioning a telescope and helping visiting astronomers during their observation run.

From → night + assistant; M.E. assistent, from L. assistent-, stem of assistens, pr.p. of assistere "assist, stand by," from → ad- "to" + sistere "take a stand, cause to stand," cognate with Pers. istâdan "to stand," → histogram.

Dastyâr "assistant," from dast "hand" (Mid.Pers. dast; O.Pers. dasta-; Av. zasta-; cf. Skt. hásta-; Gk. kheir; L. praesto "at hand;" Arm. jern "hand;" Lith. pa-žastis "arm-pit;" PIE *ghes-to-) + yâr "helper; companion" (Mid.Pers. hayyâr "helper," hayyârêh "help, aid, assistance," Proto-Iranian *adyāva-bara-, cf. Av. aidū- "helpful, useful").

An eye disease which is the difficulty in seeing at night or in dim light. Opposite of → hemeralopia. Also called → nyctalopia.

→ night; → blindness.

Same as → airglow.

→ night; → glow.

A yellow star of visual magnitude 2.84, the second brightest in the constellation → Lepus. It is a giant of → spectral type G5, lying some 159 light-years away. Nihal is double, with a companion, 2.5 seconds of arc apart.

From Ar. an-nihal (النهال) "the thirsty camels, drinking camels," plural form of an-nâhil (الناهل).

A → cardinal number between → eight and → ten.

M.E., from O.E. nigen, nigan, nigon, akin to M.Du. neghen, Du. negen, O.H.G. niun, Ger. neun, Goth. niun "nine," Pers. noh, as below; from PIE *newn "nine."

Noh, from Mid.Pers. nô; Av. nava; cognate with Skt. nava-; Gk. ennea; L. novem.

The small conical projection in the centre of the areola of each breast, which in women contains the outlet of the milk ducts. Also called: mamilla, papilla or teat (TheFreeDictionary).

M.E. nyppell, neple, "teat," from neble, diminutive of neb "bill, beak," + -le, → -ule.

Mamak, diminutive of mame "breast" in child language, maybe related to mâm, → mother.

Gaseous chemical element; symbol N. Nitrogen is the most abundant constituent of dry air. It comprises 78.09% (by volume). → Atomic number 7; → atomic weight 14.0067; → melting point -209.86°C; → boiling point -195.8°C. Nitrogen is a colorless, odorless, tasteless diatomic gas. It was discovered by the Scottish physician and chemist Daniel Rutherford in 1772.

From Fr. nitrogène, coined 1790 by Fr. chemist Jean Antoine Chaptal (1756-1832), from combining form of Gk. nitron "sodium carbonate" + Fr. gène "producing."

Azot, loan from Fr. azote, from Gk. azotos "lifeless," from negation prefix → a- + zotos "vital."

Science of → snow.

From Fr. nivologie, from niveus "snow; snowy," → snow, + -logie, → -logy.

Barfšenâsi, frp barf, → snow, + -šenâsi, → -logy.

The second satellite of → Pluto discovered in 2005 by astronomers using the → Hubble Space Telescope images. It has an estimated diameter of between 46 and 137 km and an orbital period of 24.9 days. Also called Pluto II (P2).

Nix, from Nyx in Gk. mythology the goddess of darkness and night. The conversion of "i" into "y" was to avoid conflict with the asteroid 3908 Nyx.

The proposal whereby the → Universe would not have begun with a → singularity. Instead, the → Big Bang would be an ordinary point of → space-time. The proposal, advanced by James Hartle and Stephen Hawking (1983) results from an attempt to combine aspects of → general relativity and → quantum mechanics. Based on an imaginary time assumption, it predicts a closed Universe that would start at a single point, that can be compared to the North Pole of the Earth on a two-dimensional space. Before the → Planck era there was space, but the real time began with the Big Bang event. → Hartle-Hawking initial state.

→ boundary; → hypothesis.

There are only three parameters that can be applied by an outside observer relating to a → black hole: → mass, → electric charge, and → angular momentum. The collapse of a star into a black hole wipes out all other details of its structure, and the observer can never discover any other properties of the star which formed the black hole. In other words, none of its characteristics leave any trace outside the black hole, and that is what is meant by "hair."

No, M.E., from O.E. na "never, no," cognate with Pers. na, nâ, → non-; → hair; → theorem.

Farbin, → theorem; bimuyi, noun from bimu "without hair," from bi- "without" (→ in-) + mu, → hair.
Kacali "baldness," from kacal "bald," also "crooked, bandy-legged," from kajal, from kaj "crooked, curved, bent" + → -al; probably unrelated to kal "bald," → colure.

>Noachian era = dowrân-e Nuhiyâné     دوران ِ نوحیانه

Fr.: ère noachienne

The oldest geological era on Mars, which started from the planet's birth and lasted until about 3.8 billion years ago. Features such as dried-up river valleys and delta features suggest that the climate may have been warmer and wetter. It is believed also that lakes and oceans could have existed. → Amazonian era; → Hesperian era.

The oldest geological era on Mars, which started from the planet's birth and lasted until about 3.8 billion years ago. Features such as dried-up river valleys and delta features suggest that the climate may have been warmer and wetter. It is believed also that lakes and oceans could have existed. → Amazonian era; → Hesperian era.

Noachian, named for → Noachis Terra "Land of Noah;" → era.

An extensive southern terrain of the planet Mars. One of the oldest terrains on Mars, it lies roughly between the latitudes -20° and -80° and longitudes 30° west and 30° east.

L. Noachis Terra "Land of Noah."

Zamin "land," → earth; Nuhiyâné adj. of Nuhi "related to Nuh," from Nuh (نوح) "Noah."