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

An → S-type asteroid about 34.4 × 11.2 × 11.2 km in size, which is the second-largest → near-Earth asteroid after 1036 Ganymed. It belongs to the group of → Amor asteroids. Eros was discovered on 13 August 1898 by Gustav Witt in Berlin and Auguste Charlois at Nice. It was the first asteroid orbited by an Earth probe (in 2000).

Named after the Gk. god of love Eros.

A suspension of fine solid or liquid particles in a gas.

Aerosol from aero "air" + sol(ution).

Havâlu from havâ "weather" + lu from → luyé, luyeš, → solution.

Of or relating to → asteroseismology.

→ spectropolarimetry; → -ic.

The study of the → internal structure of stars through the interpretation of their pulsation periods (→ stellar pulsation). The radial pulsations are the result of → sound waves resonating in the stars interior. Different → pulsation modes penetrate to different depths inside a star. If a large number of pulsation modes occurs, then the stellar interior, which is not directly observable, can be probed from oscillation studies because the modes penetrate to various depths inside the star. Using a complex mathematical analysis, very detailed investigations of the structure of the star's interior can be carried out. Applied to the Sun, it is called → helioseismology.

From → astero- "star," from aster-, → astro-, + → seismology.

Axtarlarzešenâsi, from axtar "star," → astro-, + larzešenâsi, → seismology.

Geology: The act or state of eroding; state of being eroded.
A general term applied to the wearing away and movement of earth materials by the action of water, glaciers, winds, gravity, etc.

From M.Fr. erosion, from L. erosionem (nom. erosio), from erodere "to gnaw away," from → ex- "away" + rodere "to gnaw, eat away" (cf. Fr. and E. animal rat).

Farsâyeš, from far- intensive prefix "much, abundant" (Mid.Pers. fra- "forward, before; much; around;" O.Pers. fra- "forward, forth;" Av. frā, fərā-, fra- "forward, forth; excessive;" cf. Skt. prá- "before; forward, in fron;" Gk. pro "before, in front of;" L. pro "on behalf of, in place of, before, for;" PIE *pro-) + verbal noun of sâyidan, variants sâbidan "to bruise, file," pasâvidan "to touch;" Khotanese sauy- "to rub;" Sogdian ps'w- "to touch;" Proto-Iranian *sau- "to rub."

Based on chemical composition, the atmosphere is divided into two broad layers: the → homosphere and the heterosphere. The heterosphere has heterogeneous chemical composition, with layered structure, of nitrogen, oxygen, helium, and hydrogen, respectively. The heterosphere begins from about 90 km from the Earth's surface and extends to space.

→ hetero-; → shere.

An → atmospheric escape mechanism that occurs where atmospheric gases are expelled en masse as a result of large body impacts, such as the cumulative effect of asteroids hits (see, e.g., Catling, D. C. and Kasting, J. F., 2017, Escape of Atmospheres to Space, pp. 129-167. Cambridge University Press).

→ impact; → erosion.

The fourth → natural satellite of → Pluto discovered in 2011 using the → Hubble Space Telescope. Also called Pluto IV (P4). It has an estimated diameter of 14-44 km, which makes it the second smallest known moon of Pluto after → Styx. Kerberos revolves around Pluto in the region between → Nix and → Hydra at a distance of about 58,000 km and makes a complete orbit roughly every 32.1 days.

Named after the three-headed dog of Greek mythology.

Combined study of the large-scale → magnetic field (→ magnetometry) and → stellar pulsations (→ asteroseismology). Magneto-asteroseismology provides strong complementary diagnostics suitable for detailed stellar modeling and permits the determination of the → internal structure and conditions within → magnetic massive  → pulsators, for example the effect of magnetism on → mixing processes. More specifically, asteroseismology yields information on the → density, → composition, and → chemical mixing in multiple internal layers (depending on the number of studied frequencies). Additionally, when rotationally split pulsation modes are observed, the internal rotation profile can be retrieved. From magnetometry surface properties are determined, related to the → chemical composition, including → starspots, and the magnetic field, such as its geometry, obliquity, and strength. Magnetic studies also provide constraints about the → stellar wind geometry and the → circumstellar environment. Moreover, the stellar → rotation period period and the → angle of inclination toward the observer are also retrieved (Buysschaert et al., 2017, astro-ph/1709.02619).

→ magneto-; → asteroseismology.

The Unicorn. An extensive but faint constellation across the celestial equator , at 7h right ascension, 4° south declination. Abbreviation: Mon; genitive: Monocerotis.

Monoceros "the unicorn," from O.Fr., from L., from Gk. monokeros, from → mono- "single" + keras "horn," kara "head," karena "head, top;" cf. Pers. soru "horn," sar "head;" L. cornu "horn," cerebrum "brain;" Skt. śiras- "head, chief;" O.E. horn "horn of an animal," also "wind instrument" (originally made from animal horns), from P.Gmc. *khurnaz (Ger. Horn, Du. horen), from PIE *ker- "head, horn, top, summit."

Takšâx, from tak "single" → mono- + šâx "horn, branch" (Mid.Pers šâk; cf. Skt. sakha- "a branch, a limb;" Arm. cax; Lith. šaka; O.S. soxa; PIE *kakhâ "branch").

A faint filamentary loop of nebulosity about 1 kpc distant, the remnant of a supernova that occurred about 300,000 years ago. It contains the Rosette Nebula as well as the Cone Nebula.

→ Monoceros; → loop.

A mirror arrangement with clock drive that reflects light from a celestial body to a fixed position. → coelostat; → heliostat.

From L. sidero-, from sidus (genitive sideris) "star, constellation" + -stat prefix denoting something that stabilizes, keeps, fixes, from -stata, from Gk. -states "one that causes to stand," or statos "standing," from *sta- "to stand."

Axtardâštâr, from axtar, → star, + dâštâr "holder, maintainer," from dâštan "to hold, maintain; to have; to possess;" Mid.Pers. dâštan; O.Pers./Av. dar- "to hold, keep back, maintain, keep in mind;" cf. Skt. dhr-, dharma- "law;" Gk. thronos "elevated seat, throne;" L. firmus "firm, stable;" Lith. daryti "to make;" PIE base *dher- "to hold, support."