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

A suffix denoting spatial or temporal direction, as specified by the initial element. Also -wards (Dictionary.com).

M.E., from O.E. -weard "toward," literally "turned toward;" PIE *wert- "to turn, wind," from *wer- "to turn, bend;" cf. Pers. gard-, gardidan "to turn, change," → revolve, → evolve.

-su, → direction.

One of the most massive → star formation regions in the → Galaxy, situated in the constellation → Aquila at the junction point of the → Galactic bar and the → spiral arms. It lies at a distance of about 6 kpc from the Sun and covers a vast area of the → Galactic plane with l = (29° to 32°) and b = (-1° to + 1°). W 43 is a complex of more than 20 → molecular clouds in ¹³CO emission with systemic velocities ranging from 12 km s^-1 to 110 km s^-1. The total → virial mass is estimated to be several 10⁶Msun. Close to its center, W 43-Main is undergoing a remarkably efficient episode of → star formation and qualifies as a mini-starburst Among the 15 dense cores of W 43-Main (0.2 pc FWHM size and 5 × 10⁵ cm^-3 density), three extremely massive, → dense cores are potentially forming → massive stars: W 43-MM1 (M = 3600 Msun), W 43-MM2 (M = 1600 Msun), and W 43-MM3 (M = 1000 Msun). Adjacent to W 43-Main is a → giant H II region, illuminated by a cluster of → Wolf-Rayet and → OB stars, emitting ~ 10⁵¹ → Lyman continuum photons per second and a → far-infrared  → continuum luminosity of ~ 3.5 × 10⁶  Lsun. It is not yet clear what the impact is of this → starburst cluster on the W 43-Main cloud located 2-10 pc away. With its special characteristics, W 43 represents a type of molecular cloud complex which hosts high luminosity embedded clusters. Other well-known examples are W 49 and W 51 (e.g., Nguyen Luong et., 2013, arXiv:1306.0547).

Number 43 in the following catalog: Gart Westerhout, 1958, Bull. Astron. Inst. Netherlands, 14, 215, A survey of the continuous radiation from the galactic system at a frequency of 1390 Mc/s.

A → boson particle that, along with → Z boson, mediates the → weak force in particle interactions. Two kinds of W bosons exist, the W⁺ and its antiparticle W^-. With a mass of 80.4 GeV/c², the W boson is almost 100 times as massive as the → proton.

W for → weak; → boson.

A member of a class of → pulsating stars with a period of 1 to 35 days located in the → instability strip of the → H-R diagram. Also known as type II Cepheid variables, W Virginis stars are typically 1.5 mag fainter than classical Type I Cepheids and have a mass less than that of the Sun. They also exhibit a period-luminosity relation which is distinct, but works in a similar way to the relation for Type I Cepheids. Hence W Virginis stars can also be used to measure Galactic and extragalactic distances.

W, alphabetical letter; → variable star designation; → Virgo; → star.

Short for → Wolf-Rayet.

→ Wolf-Rayet star.

Short for → Wolf-Rayet star.

→ Wolf-Rayet star.

The most luminous → galaxy known. It has a → redshift of z = 4.601 and a → bolometric luminosity of 3.5 × 10¹⁴Lsun. W2246-0526 hosts a deeply buried → active galactic nucleus (AGN)/→ supermassive black hole (SMBH). Discovered using the → Wide-field Infrared Survey Explorer (WISE), W2246-0526 is classified as a → hot dust-obscured galaxy, based on its → luminosity and → dust temperature (T. Diaz-Santos et al. 2015, arXiv:1511.04079).

Object designation from → Wide-field Infrared Survey Explorer (WISE).

To walk through water, snow, sand, or any other substance that impedes free motion or offers resistance to movement (Dictionary.com).

M.E. waden "to go, wade;" O.E. wadan "to go;" cf. Dan. vade, O.Fris. wada, Du. waden, Ger. waten, O.Norse vatha; akin to O.E. wæd "ford, sea," L. vadere "to go, rush," vadum "shoal, ford."

Gampidan, related to Proto-Ir. *gamp-, *gamb- "to move," cf. Dezfuli gomba, Bardesiri gopak "jump with two feet;" Sogd. (+ *â-) âγamp "walking;" (+ *uz-) Yighda žib-/žibi- "to rise, to stand," jib- "to awake;" (+ *ham-) Wakhi gəfs-/gəfst- "to run."

1) The track left by a moving ship.
2) A turbulent region appearing behind an object in a fluid which streams around the object, for example behind an aircraft in flight.

Cognate with M.L.G. wake "wake," Nor. dialect vok, O.N. vok, voka "hole in the ice."

Kel, from Tabari kel, kal "trail, track, footprint."

1) To move along on foot at a moderate pace; advance by steps.
2a) An act or instance of walking.
2b) Physics: A moving of a particle among particles. → random walk; → quantum walk.

M.E. walken, from O.E. wealcan "to toss, roll;" cf. O.N. valka "to drag about," Dan. valke "to full," M.Du. walken "to knead, press, full," O.H.G. walchan "to knead," Ger. walken "to full."

Camidan "to walk (proudly)," variant gâmidan "to walk," gâm "step, pace" (related to âmadan "to come," → consequence); Mid.Pers. gâm "step, stride, pace;" O.Pers. gam- "to come; to go;" Av. gam- "to come; to go," jamaiti "goes;" cf. Skt. gamati "goes;" Gk. bainein "to go, walk, step;" L. venire "to come;" Tocharian A käm- "to come;" O.H.G. queman "to come;" E. come; PIE stem *g^wem- "to go, come."
Puyeš, verbal noun of puyidan "to walk, run, trot; wander," from Mid.Pers. pôy-, pwd- "to run;" cf. Gk. speudein "to hasten;" Lith. spudinti.

1) An upright continuous structure that divides one area from another or surrounds an area.
2) A wall-like, enclosing part, mass, or thing .

M.E., from O.E. w(e)all "rampart, dike, cliff," also "defensive fortification around a city, side of a building" (O.Sax., O.Fris., M.L., M.Du. wal), from L. vallum "wall, rampart."

Divâr "wall," from Mid.Pers. dîvâr "wall;" related to Mid.Pers. bâr, var "enclosure, defences, fortress;" Mod.Pers. bâru "wall, rampart, fortification; fort; tower;" O.Pers. didā- "wall, stronghold, fortress;" Av. var- "castle," from var- "to cover, conceil;" Proto-Iranian *dida-vāra-; cf. Skt. dehī- "wall;" Gk. teikhos "wall;" E. dike, ditch.

A photometric system with five wavelength ranges that does not use filters. Instead it uses prisms and lenses (spectroscopy) to select the bands simultaneously. The wavelengths and the bandwidths are: W, 3250 and 140 Å; U, 3630 and 240 Å; L, 3840 and 230 Å; B, 4320 and 450 Å; and V, 5470 and 720 Å. The Walraven photometer was unique in design and remained literally unique as copies were never built. In addition, during its whole life the photometer was mounted permanently on the same telescope that had been built specifically for this instrument, the 91 cm Lightcollector' reflector, which started in 1958 at the Leiden Southern Station in Broederstroom, South-Africa. After 20 years in South-Africa the telescope and photometer were moved to the European Southern Observatory La Silla observatory in Chile. The photometric observations were resumed in March 1979 and continued for another 12 years until the decommissioning of the photometer in 1991.

After the inventors, the Dutch astronomer Theodore Walraven (1916-) and his wife Johanna Helena Walraven, née Terlinden (1920-89); → photometry.

Decreasing in strength, intensity, power, etc.

Waning, from wane, from M.E. wanen (v.), O.E. wanian "to lessen;" cf. O.S. wanon, O.N. vana, O.Fris. wania, M.Du. waenen, O.H.G. wanon "to wane, to grow less."

Kâhandé "waning, decreasing;" from kâstan, kâhidan "to decrease;" Mid.Pers. kâhitan, kâstan, kâhênitan "to decrease, diminish, lessen;" Av. kasu- "small, little" (Mod.Pers. keh); Proto-Iranian *kas- "to be small, diminish, lessen."

The crescent phase of the Moon following the → last quarter which finally disappears with setting Sun.

→ waning; → crescent.

The oval shape of the moon a few days after the → full moon and before the → last quarter.

→ waning; → gibbous.

The circumstance when the phase of the Moon is decreasing from → full moon to → new moon.

→ waning; → moon.

A state of armed conflict between states, or between groups within states.

From M.E. werre, from O.E. werre, wyrre, from Old Northern Fr. werre, akin to O.H.G. werra "confusion, strife, quarrel," Du. war "confusion, disarray," O.E. wyrsa, wiersa "worse," O.Norse verri "worse; confounded;" ultimately from PIE *wers- "to confuse, mix up."

Jang, from Mid.Pers. jang "struggle, battle, fight."

Moderately hot.

M.E.; O.E. wearm (cf. O.S., O.Fris., M.Du., O.H.G., Ger. warm, O.N. varmr, Goth. warmjan "to warm"); cognate with Pers. garm, as below.

Garm "warm;" Mid.Pers. garm "warm;" O.Pers. garma-pada "name of the fourth month" (June-July); Av. garəma- "warm; heat;" cf. Skt. gharmá "heat;" Gk. therme, thermos; L. formus "warm;" E. warm, as above; PIE base *ghworm-/*ghwerm- "warm."

A cloud of ionized gas within → active galactic nuclei (AGN) that causes absorption at → soft X-ray wavelengths. Warm absorbers were first suggested by Halpern (1984) to explain Einstein data of the quasar MR 2251-178. They are dubbed "warm" absorbers as they imply gas at temperatures of 10⁴-10⁵ K; the gas is → photoionized, not collisionally ionized. High resolution observations of warm absorbers have shown that they are outfowing. See also → cold absorber (Ceri Ellen Ashton, 2005, A Study of Warm Absorbers in Active Galactic Nuclei, Thesis, Mullard Space Science Laboratory Department of Space and Climate Physics University College London ).

→ warm; → absorber.

Meteo.: A leading edge that advances in a mass of air and replaces cooler air by warm air.

→ warm; → front.