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

Being or located on or toward the outside; external.

→ out + -er suffix of comparative degree of adjectives.

→ external.

The upper zone of the → Earth's core, just below the → mantle, extending from a depth of about 2900 km to 5100 km. It is presumed to be → liquid because it sharply reduces → compressional wave velocities and does not transmit → shear waves. Its density is from 9 to 11 g/cm³. The → temperature ranges from 4400 °C in the outer areas to 6100 °C near the → inner core. Since shear waves do not propagate through a fluid, the Earth's outer core is considered to be liquid because the shear wave velocity is zero. Convection motion within the outer core, along with the rotation of the Earth creates an effect that maintains the Earth's → magnetic field.

→ outer; → core.

A → Lindblad resonance expressed by: Ω_p = Ω + κ/m.

→ outer; → Lindblad resonance.

A planet that revolves around the Sun beyond the → asteroid belt, namely → Jupiter, → Saturn, → Uranus, and → Neptune.

→ out; → planet.

The space beyond the Earth's atmosphere.

→ outer; → space.

The act of flowing out; a fluid that flows out; any outward movement. Opposite of → inflow.

→ out + → flow.

1) General: The slow release of a gas that was trapped, frozen, absorbed or adsorbed in some material.
2) Planets: Release of the gases locked in the interior of a planet during volcanic activity so that they become part of the planet's atmosphere.

→ out + verbal noun from → gas.

1) Power which is given out by any plant or part of such plant, in the form and for the purpose required.
2) Computers: The information produced by a program or process from a specific → input.

From → out + put, from M.E. put(t)en "to push, thrust, put;" O.E. *putian.

borundâd, from borun, birun, → out, + dâd "given," p.p. of dâdan "to give" (Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," akin to L. data, → datum).

The act of extending research activities beyond its current or conventional limits to a wide section of the population for educational purposes.

→ out; reach, M.E. rechen, O.E. ræcan "to extend, hold forth;" cf. O.Fris. reka, M.Du. reiken; cognate with Pers. râst, → right.

Borun-rasâni, from borun, → out, + rasâni verbal noun of rasândan "to carry, guide, send," transitive of rasidan "to reach, arrive," → access.
Hame-âmuzi, literally "teaching every body," from hamé, → all; âmuzi, from âmuxtan "to teach; learn," → teach.

To obtain under contract with an outside supplier.

→ out; → source.

The transferring of certain business functions from internal staff to outside contractors.

Verbal noun from → outsource.

The observed presence of young stars in the immediate vicinity of the → supermassive black hole (SMBH), → Sgr A*, residing in the center of our Galaxy. The stellar population within 1 pc of the SMBH contains a variety of young and → massive stars orbiting the SMBH. Some of them are only about 20 Myr old and get as close as a few light-days to the SMBH, while from 0.1 to 0.4 pc even younger stars are found with ages of 3-7 Myr. The presence of these stars so near to the SMBH is a paradox. Their → in situ formation should be almost impossible, since the environment is too hostile for these stars to form. Indeed the strong → tidal influence of the SMBH should hamper their formation. On the other hand, the scenario considering their → migration from other places does not seem to be adequate. The time required for the migration from > 1 pc by dynamical friction would exceed their inferred ages unless the migration rate were somehow accelerated. This apparent contradiction was termed "paradox of youth" by Ghez et al. (2003, ApJ 586, L127). See also Genzel et al. (2010, Rev.Mod.Phys. 82, 3121, also at astro-ph/1006.0064).

Youth, the condition of being → young; → paradox.

The noise added in the process of reading a detector such as a CCD.

→ reading rate; → noise.

In computer science, to upgrade a system by increasing the number of nodes. For example, instead of going from a CPU of X and memory of Y to a CPU with 4X and 4Y memory, use 4 machines with CPU of X and memory of Y. This is a type of → horizontal scaling. See also → scale in, → scale up, → scale down.

→ scale; → out.

A burst of very bright → ultraviolet or → soft X-ray radiation expected to occur in → core-collapse supernovae at the instant when the → supernova shock breaks out of the stellar surface. During the collapse of the progenitor → massive star, the density in the iron core increases drastically. Once the core material reaches → nuclear density, the core rebounds generating a → shock wave that moves outward through the star. When the shock reaches the outermost layers, it ejects them out into space at → relativistic speeds.

→ shock; breakout "a forceful escape from being confined or restrained," from break, from M.E. breken, O.E. brecan (cf. Du. breken, O.H.G. brehhan, Ger. brechen), from PIE base *bhreg- "to break" (see also → fraction) + → out.

Borunzani "emergence, evasion," from borun, → out, + zani verbal noun of zadan "to strike, beat," from Mid.Pers. zatan, žatan; O.Pers./Av. jan-, gan- "to strike, hit, smite, kill" (jantar- "smiter"); cf. Skt. han- "to strike, beat" (hantar- "smiter, killer"); Gk. theinein "to strike;" L. fendere "to strike, push;" Gmc. *gundjo "war, battle;" PIE *g^when- "to strike, kill."

The cardinal point which is opposite to north. It is also the direction of the Sun at local noon (in the northern hemisphere).

M.E. suth(e), south(e), from O.E. suth "southward, in the south;" cf. O.S., O.Fris. suth "southward, in the south," M.Du. suut), O.H.G. sund, perhaps related to base of *sunnon "sun," with sense of "the region of the sun."

Note: South is related to right since it is to the right when one faces the rising Sun. This occurs in, for example, in Av., Skt., and O.Ir., as below.

Daštar, from Mid.Pers. dašn "right hand;" Av. dašina- "right;" Ossetic dæsni "skillful, dexterous;" cf. Skt. dáksina- "right; southern;" Gk. dexios (<*deks-i-uo-) "right," dexiteros "located on the right side;" L. dexter "right;" Goth. taihswo "right hand;" O.Ir. dess "on the right hand, southern;" PIE base *deks- "right." The second element -tar direction suffix, as in Mid.Pers. ošastar "east" (Av. ušastara- "eastern"), dôšastar "west" (Av. daôšatara-, daôšastara- "western"), abâxtar "north" (Av. apāxtara- "northern"), Mod.Pers. bâxtar, → west.

A region of the Earth where the inner → Van Allen belt comes closest to the Earth's surface. It is due to the fact that the → geomagnetic field is offset from the center of the Earth. The region is centered near 25 degrees South 50 degrees West, close to the Atlantic coast of Brazil. The excess of trapped energetic particles in that region presents a problem for satellites in orbit around the Earth.

→ south; → Atlantic; → anomaly.

The point in the → southern hemisphere where the → rotation axis of the Earth touches the → celestial sphere. In contrast to the → north celestial pole, no bright star is visible in that direction.

→ north; → celestial; → pole.

The point on → horizon in direction of → geographic south pole.

→ south; → point.

A large area of the south polar region of → Mars which is covered with layers of → water ice and → dust. The SPLD, like the NPLD, has a maximum relief relative to the surrounding terrain of ~ 3.5 km and ~ 1,000 km across. Above the SPLD lies a very thin temporary (1-10 m) cap of → carbon dioxide ice/frost that snows out in the winter and sublimates over the spring and summer seasons. It is believed that the rhythmic nature of the deposits is related to oscillations in Mars' → orbital parameters (J. J. Plaut et al., 2007, Science 316, 92).

→ south; → polar; → layer; → deposit.