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

The outermost of Jupiter's known confirmed satellites, also known as Jupiter IX, discovered by Seth B. Nicholson (1891-1963) in 1914. With a visual magnitude of 18.3, it has a diameter of 28 km and orbits Jupiter at a mean distance of 23,848,000 km every 753 days.

In Gk. mythology a Naias Nymphe who was abducted by Zeus to a Black Sea coast where the city of Sinope was named for her. According to most sources, she tricked Zeus into swearing an oath promising her her virginity.

Having the characteristics of a sine function; same as → sine wave.

From sinus, → sine, + → -al.

1) To drink (a liquid) a little at a time; take small tastes of.
2) An instance of sipping; a small taste of a liquid; a small quantity taken by sipping (Dictionary.com).

M.E. sippen (v.), akin to Low German sippen "to sip."

Cašel, from Pashto cašəl "to drink," caceq "to drip;" related to cašidan "to taste," → taste.

A ∩-shaped tube with unequal arms that is used to move a liquid from one level to a lower level via a third level higher than either. Once the short arm is filled, for example, by suction, the liquid flows down in the long arm under the action of gravity due to mass excess in it.

From Fr. siphon, from L. sipho (genitive siphonis), from Gk. siphon "pipe, tube," of unknown origin.

The white star in the constellation → Canis Major that is the brightest star of the sky (V = -1.46). Its other designations include HD 48915, HR 2491, and BD-16°1591. Its particular brightness is mostly due to its proximity to the Earth, being a mere 8.6 → light-years away, the fifth closest star system. Sirius is a → dwarf star of → spectral type A0 or A1 V with an → effective temperature of 9,880 K, a mass of 2.063 ± 0.023 Msun (Bond et al., 2017, ApJ 840, 70), and a → luminosity of 26 Lsun. Sirius has a radius of 1.75 solar and a minimum equatorial rotation speed of 16 km s^-1. Its → rotation period is less than 5.5 days. This star is a → visual binary (separation 4.6 arcsec, period 50 years), the companion → Sirius B being the first → white dwarf to be discovered. Sirius is a → metal-rich star, its iron content triple that of the Sun, most likely from some sort of → element diffusion.

From L. Sirius, from Gk. Seirios, literally "scorching," because of its brightness.

Tištar, from Mid.Pers. Tištar, from Av. Tištrya- "(name of the deified star) Sirius," literally "the one who belongs to the three stars," in reference to the three stars of → Orion's Belt; ultimately from PIE *tri-str-o-m- "group of three stars," then *tri-str-iia- and by dissimulation Indo-Iranian *ti-str-iia-, Av. *Tištriia- and Vedic Skt. Tisyà (A. Panaino, in Iranica, under Tištrya).

Same as → companion of Sirius.

→ Sirius; B, letter of alphabet by convention.

Same as → Alpheratz.

Sirah, contraction of Ar. As-Surrat al-Faras (السره‌الفرس) "The Horse's Navel," from surrat (سره) "navel" + faras (فرس) "horse." The name refers to the location of the star in the figure of → Pegasus. However, the star is now considered to belong to the constellation → Andromeda.

Ra's-ol-Mosalsalé, from Ar. Ar-Ra's al-Mar'ah al-Musalsalah "The head of the chained woman," from Ra's "head" + Mar'ah "woman" + Musalsalah "chained".

In a → superheterodyne receiver, a → mixer which consists of a sandwich structure of two superconducting leads separated by a thin isolator. SIS mixers give a good noise performance especially for → millimeter wavelengths.

SIS, acronym for Superconductor-Insulator-Superconductor; → mixer.

A female person having the same parents as another person.

M.E. suster, sister, from O.E. sweostor, swuster or Old Norse systir, in either case ultimately from PIE *swesor; cf. Skt. svásar-, Av. x^vaηnhar-, Pers. xâhar, xwâhar, as below, Gk. eor, L. soror (Fr. sœur), O.C.S., Rus. sestra, O.Ir. siur, Sw. syster, Dan. soster, O.Sax. swestar, M.Du. suster, Du. zuster, O.H.G. swester, Ger. Schwester.

Xâhar, xwâhar, from Mid.Pers. xwah(ar) "sister;" Av. x^vaηnhar- "sister;" cf. Khotanese hvar- "sister;" cognate with E. sister, as above.

1) To rest with the body supported by the buttocks or thighs; be seated.
2) To be located or situated.

Nešastan "to sit down; to settle down; to sink;" Mid.Pers. nišastan "to sit;" O.Pers. nišādayam [1 sg.impf.caus.act.] "to sit down, to establish," hadiš- "abode;" Av. nišasiiā [1 sg.subj.acr.] "I shall sit down," from nihad- "to sit down," from → ni- "down; into" + had- "to sit;" PIE base *sed- "to sit;" cf. Skt. sad- "to sit," sidati "sits;" Gk. hezomai "to sit," hedra "seat, chair;" L. sedere "to sit;" O.Ir. suide "seat, sitting;" Welsh sedd "seat;" Lith. sedmi "to sit;" Rus. sad "garden;" Goth. sitan, Ger. sitzen; E. sit. See also: → reside, → settle.

The position or location of a building, observatory, etc. especially as to its environment. → astronomical site.

M.E., from L situs "position, arrangement, site," from sinere "to let, leave alone, permit," cognate with Av. šiti- "place, abode, residence," as below.

Sit, from Av. šiti- "place, abode, residence," šitāy- "habitation, dwelling," from ši- "to live;" cognate with Skt. ksay- "to live, to stay," kséti "he dwells;" Gk. ktizein "to inhabit, build;" L. situs "position, site; situated."

The process of choosing a site for an astronomical observatory based on meteorology, seeing conditions, and access to the site.

→ site; → selection.

To place in a site or context; to locate.

From M.L. situatus, p.p. of situare "to place, locate," from L. situs "place, position."

Sitidan, from sit, → site, + -idan infinitive suffix.

Having a site, situation or location.

P.p. of → situate.

1) The manner of being placed with respect to surroundings.
2) Momentary state; a set of circumstances.

Verbal noun of → situate.

A cardinal number, five plus one.

M.E. six, sex; O.E. siex, syx, seox, sex, from P.Gmc. *sekhs (cf. O.S. seks, O.N., O.Fris. sex, M.Du. sesse, Du. zes, O.H.G. sehs, Ger. sechs, Goth. saihs), from PIE *seks-, cognate with Pers. šeš, as below.

Šeš, from Mid.Pers. šaš; Av. xšuuaš- "six;" cf. Skt. sás- "six;" Gk. hex; L. sex (Fr. six; Sp. seis); O.C.S. sesti; Lith. sesi; O.Ir. se; Welsh chwech; E. six, as above.

A cardinal number, ten times six. → sexagesimal.

M.E.; O.E. sixtig, from → six + -tig a suffix of numerals denoting multiples of ten.

Šast "sixty;" Mid.Pers. šast "sixty;" Av. xšuuašti- "sixty;" cf. Skt. sasti- "six;" L. sexaginta "sixty."

The spatial dimensions, extent, proportions, amount, or degree of something.

M.E. syse originally "control, regulation, limit," from O.Fr. sise shortened form of assise "session, regulation, manner."

1) Andâzé "measure, size" from Mid.Pers. andâzag, handâcak "measure," handâxtan, handâz- "to measure," Manichean Mid.Pers. hnds- "to measure," Proto-Iranian *hamdas-, from ham-, → com-, + *das- "to heap, amass;" cf. Ossetic dasun/dast "to heap up;" Arm. loanword dasel "to arrange (a crowd, people)," das "order, arrangement,"

The number of → edges.

→ size; → graph.

A quantity that defines the type of → scattering.

→ size; → parameter.