An Etymological Dictionary of Astronomy and Astrophysics

The effect of → gravitational potentials on the → anisotropy of the → cosmic microwave background radiation,
in which photons from the → CMB are gravitationally → redshifted,
causing the CMB spectrum to appear uneven. This effect is the predominant source of fluctuations in the CMB for angular scales above about 10 degrees. It involves two parts: the effect of the potential at the → surface of last scattering, which is the ordinary Sachs-Wolfe effect. And the integrated Sachs-Wolfe (ISW) effec, which is caused by the time variation of gravitational potentials as the photons travel through them. A photon traveling through a decaying → potential well (wall) gains (loses) energy. Without → dark energy the photon is → blueshifted and then → redshifted, so that both effects compensate each other. On the other hand, in an → accelerating Universe driven by dark energy the photon gets more blueshifted. See also → Rees-Sciama effect.

See also: Rainer Kurt Sachs (1932- ) & Arthur Michael Wolfe (1939- ), 1967, ApJ 147, 73; → effect.

An almost horizontal region in the → CMB angular power spectrum belonging to a → multipole index 10 ≤ l ≤ 100. This feature is due to the → Sachs-Wolfe effect.

See also: → Sachs-Wolfe effect; → plateau.

A supergiant star of type G2 Ib situated in the constellation → Aquarius. At a distance of 750 light-years, it has a luminosity 3000 times that of the Sun, and a diameter about 60 times the solar diameter. Variant designations: Sadalmelek; Sadlamulk; El Melik; Saad el Melik.

See also: From Ar. Sa’d al-Malik (سعد الملک) “the lucky star of the ruler,”
for unknown reasons.

The star that lies at the center of → Cygnus’s → Northern Cross. This F8 → supergiant is situated some 1,500 → light-years away and has an → apparent visual magnitude of 2.20.

See also: From Ar. as-sadr (الصدر) “breast” (of the Cygnus).

The Arrow. A very small → constellation,
in fact the third smallest constellation in the sky, lying south of → Vulpecula, and north of → Aquila. The constellation contains the prototype → WZ Sagittae star and M71 (NGC 6838), formerly thought to be an → open cluster but now considered to be a → globular cluster of low condensation. Its brightest star α Sge is a yellow bright → giant of → apparent magnitude +4.37 and → spectral type G1 II about 475 → light-years from Earth.
Abbreviation: Sge; Genitive: Sagittae.

Etymology (EN): From L. sagitta “arrow.”

Etymology (PE): Peykân, → arrow.

The Archer. A large constellation belonging to the → Zodiac, situated between → Scorpius and → Capricorn. It is located in the southern hemisphere at approximately 19h right ascension, 25° south declination. The constellation, part of which lies in the → Milky Way, contains the → Trifid Nebula, → Lagoon nebula, star clusters, and globular clusters. The center of the Galaxy lies in the direction of Sagittarius. Abbreviation: Sgr; Genitive: Sagittarii.

Etymology (EN): From L. sagittarius “archer,” literally “pertaining to arrows,” from → sagitta “arrow” + -arius “-ary.” In Gk. mythology, Sagittarius is identified as a centaur, half human, half horse.

In some legends, the Centaur Chiron was the son of Philyra and Saturn, who was said to have changed himself into a horse to escape his jealous wife, Rhea. Chiron was eventually immortalized in the constellation of → Centaurus, or in some version, Sagittarius.

Etymology (PE): Nimasb, from Mid.Pers. nêmasp “centaur, Sagittarius,” from nêm, nêmag “mid-, half” (Mod.Pers. nim); Av. naēma- “half;” cf. Skt. néma- “half” + asp “horse” (Mod.Pers. asb);
O.Pers. asa- “horse;” Av. aspa- “horse,” aspā- “mare,” aspaiia- “pertaining to the horse;” cf. Skt. áśva- “horse, steed;” Gk. hippos;
L. equus; O.Ir. ech; Goth. aihwa-; O.E. eoh “horse;” PIE base *ekwo- “horse.”

A strong radio source at the center of our Galaxy. It is a complex object with three components: Sgr A West is a thermal radio source made of several dust and gas clouds, which orbit → Sgr A* and fall onto it at velocities as high as 1000 km per second.

Sgr A East is a → non-thermal source, about 25 → light-years across, that appears to be a → supernova remnant.

Sgr A* is the most plausible candidate for the location of a Galactic → supermassive black hole with a mass of about 4 million → solar masses.

See also: → Sagittarius.

One of the → spiral arms of the Milky Way Galaxy. It lies between the Sun and the the → Scutum-Crux arm. Also known as the Sagittarius-Carina Arm.

See also: → Sagittarius; → arm.

A massive (3 × 10⁶ → solar masses), dense (up to 10⁸ particles per cm³) → H II region and → molecular cloud complex located near the → Galactic center (about 390 → light-years from it) and
about 26,000 light-years from Earth. This complex is one of the largest in the → Milky Way, spanning a region about 150 light-years across. The mean → hydrogen  → density within the cloud is 3,000 atoms per cm³, which is about 20-40 times denser than a typical molecular cloud. It is the richest molecular source in the Galaxy in which many different types of → interstellar molecule have been identified, including glycine, the simplest amino acid, and the sugar molecule glycoaldehyde.

See also: → Sagittarius.

A satellite galaxy of the Milky Way discovered only in 1994 since most of it is obscured by the Galactic disc. At only 50,000 light years distant from our Galaxy’s core, it is travelling in a polar orbit around the Galaxy. Our Galaxy
is slowly devouring it, as evidenced by a filament which stretches around the Milky Way’s core like a gossamer loop. It is only about 10,000 light-years in diameter, in comparison to the Milky Way’s diameter of 100,000 light years. It is populated by old yellowish stars has four known globular clusters: M54, Arp 2, Terzan 7, and Terzan 8. It should not be confused with the → Sagittarius Dwarf Irregular Galaxy.

See also: → Sagittarius; → dwarf; → elliptical; → galaxy.

A dwarf irregular galaxy, discovered in 1977, that is a member of the Local Group of galaxies. It has a diameter of 1,500 light-years and lies about 3.5 million light-years away.
SagDIG contains as much as about 10⁸ solar masses of H I gas and is one of the most metal-poor galaxies. It should not be confused with the → Sagittarius Dwarf Elliptical Galaxy.

See also: → Sagittarius; → dwarf; → irregular; → galaxy.

The → phase difference between two light waves moving in opposite directions along a closed circular loop when the loop is rotating. More specifically, consider
a beam of light split into two beams which are then allowed to propagate in two opposite directions along the rim of a rotating disk. When they are recombined, a phase difference
occurs between them. The position of the → interference fringes is dependent on the → angular velocity of the setup. This → relativistic effect illustrates the impossibility of synchronizing clocks situated in a rotating → reference frame, as described by Einstein in 1905. The Sagnac effect is used, for example, in optical gyroscopes installed in airplanes or in devices used for measuring the Earth rotation. The Sagnac effect is very important for the correct working of the → Global Positioning System.

See also: Named after Georges Sagnac (1869-1928), French physicist, who discovered the phenomenon in 1913; → effect.

An equation that gives the number of atoms of a given species in various stages of
→ ionization that exist in a gas in
→ thermal equilibrium as a function of the temperature, density, and ionization energies of the atoms.

See also: Named after the Indian astrophysicist Megh Nad Saha (1894-1956), who first derived the equation in 1920; → equation.

A blue/violet light better seen at night on a pointed object, such as the mast of a
ship or the wing of an airplane, during a → thunderstorm. The mast appears to be on fire but does not burn. It occurs when the ground below the storm is electrically charged, and there is high voltage in the air between the cloud and the ground. The high voltage causes the electrons and protons of the air molecules to be pulled away from each other, transforming the air into a glowing ionized gas. St. Elmo’s fire is sometimes mistaken for → ball lightning. It was identified as an electrical phenomenon first by by Benjamin Franklin in 1749. Also called → corposant.

Etymology (EN): Saint Elmo the Italian rendering of St. Erasmus of Formiae (died 303) the patron saint of Mediterranean sailors; → fire.

Etymology (PE): Âtaš, → fire, sepant “saint, holy,” → heiligenschein.

A → supergiant star of visual magnitude 2.06 and → spectral type B0.5 Ia marking the right knee of Orion. It is about 700 light-years away.

See also: Saiph “sword,” from Ar. as-saiph al-jabbâr (سیف الجبار) “the Sword of the Giant.”

The three conditions that are necessary for the generation of a → baryon asymmetry in the → early Universe. These conditions are:

1. The → baryon number should not be → conserved.
   

2. The → charge conjugation and → CP symmetry should be → violated, and
   

3. Departure from → thermal equilibrium.

See also: Named after Andrei Sakharov (1921-1989), who in 1967 described these three minimum conditions (A. D. Sakharov, 1967, Zh. Eksp. Teor. Fiz. Pis’ma 5, 32; 1967, JETP Lett. 91B, 24); → condition.

A → post-asymptotic giant branch star that in 1995 underwent sudden re-brightening due to a
→ helium shell flash, or
→ very late thermal pulse (VLTP), before embarking on
a → white dwarf cooling track.
Such an outburst is very rare, and in this case it is the first seen in modern times. Stellar outbursts observed in 1670 (nova CK Vul) and 1918 (nova V605 Aql) may have been caused by the same phenomenon. Since 1995, Sakurai’s Object has undergone observable changes on time-scales of weeks to months. Several phases of dust production followed the outburst, with a deep optical minimum beginning in early 1999, such that any changes in the central star have since been inferred from radio and infrared observations. Subsequent observations and modeling have revealed much about the dust shell formation and the outer regions of the ejecta. This object is also the central star of an extended very faint planetary nebula (→ CSPN), confirming that the latest large mass ejection during the planetary nebula phase occurred several thousands years ago (see, e.g. H. L. Worters et al. 2009, MNRAS 393, 108 and references therein).

See also: Named after Yukio Sakurai, a Japanese amateur astronomer, who serendipitously discovered it on February 20, 1996, when searching for comets;
→ object.

The first mathematical description of the → initial mass function (IMF) of newly formed stars of solar to → intermediate-masses. It is proportional to M ^-2.35, where M is the stellar mass. → Salpeter slope.

See also: Named after the Austrian-Australian-American astrophysicist Edwin Ernest Salpeter (1924-2008); → function.

An equation describing how the nuclei of helium fuse together,
in the interior of giant stars, to form carbon nuclei. → triple-alpha process.

See also: Named after the Austrian-Australian-American astrophysicist Edwin Ernest Salpeter (1924-2008); → process.

The value of the exponent in the → initial mass function as
derived by Salpeter (1955) for solar to → intermediate mass stars in the Solar neighborhood: &Gamma = 1.35 or &alpha = 2.35,
or x = -1.35. Also known as Sapleter index.

See also: → Salpeter function; → slope.

1. A crystalline compound, sodium chloride, NaCl, occurring as a mineral, used for food seasoning and preservation.
   
2. Chem.: A solid compound formed when the hydrogen of an acid has been replaced by a metal.

Etymology (EN): O.E. sealt; cf. O.N., O.Fris., Goth. salt, Du. zout, Ger. Salz from PIE *sal- “salt;” cf.
Gk. hals (genitive halos) “salt, sea;” L. sal; O.Ir. salann; Welsh halen;
O.C.S. sali “salt.”

Etymology (PE): Namak “salt;” Mid.Pers. namak “salt.”

Oceanography: One of several alternating columns of rising and descending water resulting from a → mixing process that occurs when warm salty water overlies a colder and relatively fresher layer of water. If the overlying salty water loses enough heat, it sinks down into the colder, fresher water, lengthening into a finger of salty water. Becuse the finger loses heat faster than it loses salt, the salt finger will continue to sink (salty water is denser than fresh water of the same temperature). Hence the salt finger loses more heat and displaces the colder water around it, which rises up and mixes into the warm salty layer above. Salt fingers are an example of → double-diffusive convection and play an important role in oceanic mixing. See also → fingering instability, → fingering convection.

See also: → salt; → finger.

A chemical compound, potassium nitrate, KNO₃. It is a naturally occurring mineral source of nitrogen, and is used in the manufacture of fireworks, fluxes, gunpowder, etc.

Etymology (EN): M.E. sal peter, salpetre, from O.Fr. salpetre, from M.L. sal petrae “salt of rock,” from L. sal, → salt

• petra “rock, stone.”

Etymology (PE): Šuré, related to šur “salty;” Mid.Pers. šôr “salty,” šorag “salt land;” cf. Skt. ksurá- “razor, sharp knife;” Gk. ksuron “razor;” PIE base *kseu- “to rub, whet.”

Statistics: A portion of the units of a population. The units are selected based on a randomized process with a known probability of selection. The sample is used to make inferences about the population by examining or measuring the units in the sample. → specimen = nemuné (نمونه).

Etymology (EN): M.E., from O.Fr. essample, from L. exemplum “a sample,” literally “that which is taken out,” from eximere “to take out, remove.”

Etymology (PE): Nemunân, from nemun, from nemudan “to show;” Mid.Pers. nimūdan, nimây- “to show,” from O.Pers./Av. ni- “down; into,” → ni- (PIE), + māy- “to measure;” cf. Skt. mati “measures,” matra- “measure;”
Gk. metron “measure;” L. metrum; PIE base *me- “to measure.”

Statistics: Each possible outcome in a → sample space.

See also: → sample; → point.

The number of sampling units which are to be included in the sample. In the case of a multi-stage sample this number refers to the number of units at the final stage in the sampling.

See also: → sample; → size.

Statistics: A set which consists of all possible outcomes of a random experiment.

See also: → sample; → space.

The act, process, or technique of selecting a number of cases from all the cases in a particular population.

Etymology (EN): → sample + → -ing.

Etymology (PE): Nemunân-giri, literally “taking sample,” from nemunân→ sample + giri verbal noun of gereftan “to take, seize, hold;” Mid.Pers. griftan, gir- “to take, hold, restrain;” O.Pers./Av. grab- “to take, seize,”
cf. Skt. grah-, grabh- “to seize, take,” graha- “seizing, holding, perceiving,” M.L.G. grabben “to grab,” from P.Gmc. *grab, E. grab “to take or grasp suddenly;” PIE *ghrebh- “to seize.”

That part of the difference between the expected value of the sample estimator and the true value of the characteristic which results from the sampling procedure, the estimating procedure, or their combination.

See also: → sampling; → bias.

That part of the difference between a population value and an estimate thereof, derived from a random sample, which is due to the fact that only a sample of values is observed; as distinct from errors due to imperfect selection, bias in response or estimation, errors of observation and recording, etc.

See also: → sampling; → error.

Same as → Nyquist-Shannon sampling theorem.

See also: → sampling; → theorem.

One of the units into which an aggregate is divided for the purpose of sampling, each unit being regarded as individual and indivisible when the selection is made.

See also: → sampling; → unit.

Hard granular powder, consisting of fine grains of rock or minerals, usually quartz fragments, found on beaches, in deserts, and in soil.

Etymology (EN): O.E. sand; cf. O.N. sandr, O.Fris. sond, M.Du. sant, Ger. Sand; PIE base *samatha- (cf. Gk. psammos “sand,” L. sabulum).

Etymology (PE): Mâsé “sand,” of unknown origin.

Variously colored → sedimentary rock composed mainly of sand-like quartz grains cemented by calcite, clay, or iron oxide.
The sand accumulated originally underwater in shallow seas or lakes, or on the ground along shorelines or in desert regions.

See also: → sand; → stone.

A strong wind carrying sand through the air.

See also: → sand; → storm.

A deep → objective prism survey of the → Large Magellanic Cloud carried out with the Curtis Schmidt telescope on Cerro Tololo in Chile. A total of 1272 stars, generally brighter than → photographic magnitude ~ 14, are listed in the catalog as proven or probable LMC members. The stars are identified on the charts in the LMC Atlas of Hodge & Wright (1967).

See also: By Nicholas Sanduleak (1933-1990), American astronomer, published in 1970 as Contribution No. 89 of the Cerro Tololo Inter-American Observatory; → catalog.

One of the 5 or 6 → epagomenal days added to the 12 months of 30 days each in the → French Republican Calendar. Sansculottides began on September 17 or 18 and approximately ended on the → autumnal equinox, on September 22 or 23 of the → Gregorian calendar. These days were kept as festivals of Virtue, Genius, Labor, Opinion, and Rewards. There was a sixth Sanculottide, called Revolution, in → leap years.

See also: From Fr. sans-culotte, literally “without knee breeches,”
a revolutionary of the lower class in the French revolution. The appellation was originally a term of contempt applied by the aristocrats but later was adopted as a popular name by the French revolutionaries. It refers to the fashionable culottes (silk knee breeches) of the aristocrats as distinguished from the working class sans-culottes, who traditionally wore pantalons (long trousers).

A general whole-sky catalog compiled by the Smithsonian Astrophysical Observatory which results from the combination of several earlier catalogs.
The compilation gives positions and proper motions for 258,997 stars, of which 8,712 are double and 499 variable, with an average distribution of 6 stars per square degree. The star positions have an average standard deviation of 0’’.2 at their original epochs (0’’.5 at epoch 1963.5). The equinox is 1950.0 and the system that of the FK4.

Etymology (EN): SAO acrynome of the Smithsonian Astrophysical Observatory;
→ star; → catalog.

The period of 223 → synodic month, equaling 6585.32 days or 18 years, 11.33 days, after which the Sun, Earth, and Moon return to approximately the same relative geometry. When two eclipses are separated by a period of one Saros, they occur at the same node with the Moon at nearly the same distance from Earth and at the same time of year. Thus, the Saros is a useful tool for organizing eclipses into families or series. Each series typically lasts 12 or 13 centuries and contains 70 or more eclipses (F. Espenak, NASA).

See also: Gk. saros, from Akkadian shār, Sumerian shar “multitude, large number.”

The ancient astronomers knew the Saros cycle, but they did not use the term Saros. In the Almagest, Ptolemy refers to the Saros as the “periodic time” (periodikos chronos) and gives it the following properties: 223 → synodic months = 239 → anomalistic months = 242 → draconistic months = 6,585 ¹/₃ days = 241 revolutions in longitude plus 10 ²/₃ degrees. Edmund Halley seems to have been the first to apply this term to an eclipse cycle, in 1691.

1. A body that revolves around a planet; a moon. → Galilean satellite; → regular satellite; → irregular satellite.
   

2. Something that depends on, accompanies, or serves something else. → satellite galaxy; → satellite line.

Etymology (EN): From M.Fr. satellite, from L. satellitem “attendant.”

Etymology (PE): 1) Mâhvâré, from mâh, → moon, + -vâré, -vâr similarity suffix.
2) Bandevâr, from bandé “bound, fastened; (devoted) servant, domestic;” Mid.Pers. bandag,
from bastan, band-, vastan “to bind, shut” (O.Pers./Av. band- “to bind, fetter,” banda- “band, tie” (cf.
Skt. bandh- “to bind, tie, fasten;” PIE *bhendh- “to bind;” Ger. binden; E. bind).

A galaxy that orbits a larger one due to gravitational attraction. The Milky Way has at least ten satellite galaxies: the Large Magellanic Cloud, the Small Magellanic Cloud, Ursa Minor Dwarf, Draco Dwarf, Sculptor Dwarf, Sextans Dwarf, Carina Dwarf, Fornax Dwarf, Ursa Major I, and → Sagittarius Dwarf Elliptical Galaxy.

See also: → satellite; → galaxy.

Radio astro.: Of an OH source, which emits at 1665 and 1667 MHz as the main frequencies, one of the lines arising from transitions at 1612 and 1730 MHz.

See also: → satellite; → line.

1. Chem.: To add as much of a liquid, solid, or gas to a solution as it can absorb at a given temperature.
   
2. To fill something with so many things that no more can be added.

Etymology (EN): From L. saturatus, p.p. of saturare “to fill full, sate, drench,” from satur “sated, full,” from PIE base *sā- “to satisfy.”

Etymology (PE): Anjâlidan “to saturate, to fill” (Dehxodâ, Steingass), ultimately from Proto-Iranian *ham-gar-, from *ham- “together,” denoting “much, many,”
→ syn-, + *gar- “to soak, moisten;” cf. Sogdian wγyr- “to soak, steep,” from *aua-gar-, from which derives Pers. âqâridan, âqeštan “to steep, soak; mix.”

1. Chem.: The qualifier of a solution that has as much solute as possible.
   

2. (Of colors) Of maximum chroma or purity.

See also: Past participle of → saturate (v..

Air that contains the maximum amount of → water vapor that is possible at the given → temperature and → pressure, i.e. air in which the → relative humidity is 100%.

See also: → saturated; → air.

A liquid whose temperature and pressure are such that any decrease in pressure without change in temperature causes it to boil.

Etymology (EN): → saturate; → liquid.

A solution which can exist in equilibrium with excess of solute. The saturation concentration is a function of the temperature.

Etymology (EN): → saturate; → solution.

A vapor at the pressure and temperature at which it can exist in dynamical equilibrium with its liquid. Any compression of its volume at constant temperature causes it to condense to liquid at a rate sufficient to maintain a constant pressure. The term “saturated” is a misnomer, since it does not have the same meaning as a → saturated solution in chemistry. There is no question of one substance being dissolved in another.

Etymology (EN): → saturate; → vapor.

Physics: Degree of magnetization of a substance which cannot be exceeded however strong the applied magnetizing field.
Detectors: The condition of a detector or a pixel when it is submitted to a signal so strong that it cannot handle it properly; the result is a non-linear, useless response.

See also: Verbal noun of → saturate.

The maximum current that can be obtained in a specific circuit under specified conditions.

See also: → saturation; → current.

The maximum intrinsic magnetic induction possible in a material.

See also: → saturation; → induction.

In radar, a signal whose amplitude is greater than the dynamic range of the receiving system.

See also: → saturation; → signal.

The sixth → planet from the Sun and the second largest with an equatorial diameter of 120,536 km orbiting at an average distance of 1,429,400,000 km (9.54 → astronomical units) from Sun. With an → eccentricity of 0.05555,
its distance from the Sun ranges from 1.35 billion km (9.024 AU) at its → perihelion to 1.509 billion km (10.086 AU) at its → aphelion.

Its average orbital speed being 9.69 km/s, it takes Saturn 29.457 Earth years (or 10,759 Earth days) to complete a single revolution around the Sun. However, Saturn also takes just over 10 and a half hours (10 hours 33 minutes) to rotate once on its axis. This means that a single year on Saturn lasts about 24,491 Saturnian solar days.

Saturn has a mass of 5.6836 × 10²⁶ kg (95.159 → Earth masses) and a mean density of 0.687 g cm^-3.

Like Jupiter, Saturn is about 75% → hydrogen and 25% → helium with traces of → water, → methane, and → ammonia, similar to the composition of the primordial Solar Nebula from which the solar system was formed.

The temperature on Saturn is ~ -185 °C.

Like Jupiter, Saturn has a solid core of iron-nickel and rock (silicon and oxygen compounds). The core has an estimated mass of 9-22 Earth Masses and a diameter of about 25,000 km (about 2 Earth diameter). The core is enveloped by a liquid → metallic hydrogen layer and a → molecular hydrogen layer. Saturn’s interior is hot (12,000 K at the core). The planet radiates more energy into space than it receives from the Sun. Most of the extra energy is generated by the → Kelvin-Helmholtz mechanism as in Jupiter. Saturn has 62 known satellites. → Saturn’s ring. On 1 July 2004 NASA/ESA’s → Cassini-Huygens became the first to orbit Saturn, beginning a 13 year mission that revealed many secrets and surprises about Saturn and its system of rings and moons.

Etymology (EN): O.E. Sætern “Italic god,” also “most remote planet” (then known), from L. Saturnus, Italic god of agriculture, possibly from Etruscan.

Etymology (PE): Keyvân Mid.Pers. Kêwân, borrowed from Aramean kâwân, from Assyrian kaiamânu.

A planetary nebula in the Aquarius constellation discovered by William Herschel in 1782.
It has a size of about 0.3 x 0.2 light-years and lies about 1400 light-years away. Also known as NGC 7009.

See also: → Saturn, such named by Lord Rosse in the 1840s, because the object has a vague resemblance to the planet Saturn in low-resolution telescopes;
→ nebula.

A system of rings around Saturn made up of countless small particles, ranging in size from micrometers to meters, that orbit the planet. The ring particles are made almost entirely of → water ice, with some contamination from → dust and other chemicals. The ring system is divided into six major components: D, C, B, A, F, and G rings, listed from inside to outside. But in reality, these major divisions are subdivided into thousands of individual → ringlets. The large gap between the A and B rings is called the Cassini division. Saturn’s rings are extraordinarily thin: though they are 250,000 km or more in diameter, they are less than one kilometer thick. → A ring, → B ring, → C ring, → D ring, → F ring, → G ring.

See also: → Saturn; → ring.

1. To rescue from danger or possible harm, injury, or loss.
   

   2. To keep safe, intact, or unhurt; safeguard; preserve.
      

   3. Computers: To copy (a file) from RAM onto a disk or other storage medium (Dictionary.com).

Etymology (EN): M.E. sa(u)ven, from O.Fr. sauver “keep (safe), protect, redeem,” from L.L. salvare “make safe, secure,” from L. salvus “safe;” ultimately from PIE root *sol- “whole,” → general.

Etymology (PE): Bužidan, variants
buxtan, boxtan “to save, liberate;” boxt “saved, redeemed;” Mid.Pers. bôz- “to free, to release;” Bactrian βoγ “to save;” Av. bûj- “to save, redeem;” cf. Baluci bôtk / bôj “to open”, butk / busk “to be released (from jail), be fired (a gun), be emptied;” Pers.

buzidan/buz- “to pluck off hair, wool;”

cf. Gk. phugo, L. fugio “I flee”, Goth. us-baugjan “to wipe off” (Cheung 2007).