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

An equatorial mounting in which the declination axis is at the end of the polar axis, which is on top of a pier to raise the telescope to a convenient height.

German, from L. Germanus, maybe of Gaulish (Celtic) origin, perhaps originally meaning "noisy" (cf. O.Ir. garim "to shout") or "neighbor" (cf. O.Ir. gair "neighbor"); → mounting.

Barnešând, → mounting; Âlmâni "German," from Âlmân, from Fr. Allemand "German," from P.Gmc. *Alamanniz, probably meaning "all-man" and denoting a wide alliance of tribes. Alternatively, perhaps meaning "foreign men," cognate with L. alius "the other."

A layer of icy molecules covering interstellar dust grains.

→ grain; mantle, from O.E. mentel "loose, sleeveless cloak," from L. mantellum "cloak," perhaps from a Celtic source.

Rupuš "overgarment, cloak," from ru "surface, face; aspect; appearance" (Mid.Pers. rôy, rôdh "face;" Av. raoδa- "growth," in plural form "appearance," from raod- "to grow, sprout, shoot;" cf. Skt. róha- "rising, height") + puš "covering, mantle," from pušidan "to cover; to put on" (Mid.Pers. pôšidan, pôš- "to cover; to wear;" cf. Mid.Pers. pôst; Mod.Pers. pust "skin, hide;" O.Pers. pavastā- "thin clay envelope used to protect unbaked clay tablets;" Skt. pavásta- "cover," Proto-Indo-Iranian *pauastā- "cloth").

A way of testing the quality of optical systems. In this method, incident rays from a point source are isolated by small holes in an opaque screen located close to the lens or mirror under test. Photographic plates are inserted into the beam within and beyond the focal region. The black dots on the exposed plates, which reveal differences of optical focus in the various zones of the lens or mirror, are analyzed to yield the objective's figure. → Shack-Hartmann wavefront sensor.

Named after the German astronomer Johannes Hartmann (1865-1936), who developed the method. → test.

An → orbital maneuver using two timed engine impulses to move a spacecraft between two coplanar circular orbits. It is performed through an elliptic orbit which is tangent to both circles at their periapses (→ periapsis).

→ Hohmann transfer orbit.

An elliptical orbit that is the most economical path for a spacecraft to take from one planet to another. In the case of Earth-Mars travel, the desired orbit's → perihelion will be at the distance of Earth's orbit, and the → aphelion will be at the distance of Mars' orbit. The portion of the solar orbit that takes the spacecraft from Earth to Mars is called its trajectory. Earth and Mars align properly for a Hohmann transfer once every 26 months. → Hohmann transfer.

Named after Walter Hohmann (1880-1945), German engineer, who developed basic principles and created advanced tools necessary for the conquest of space. In 1925 he published The Attainability of the Heavenly Bodies in which he described the mathematical principles that govern space vehicle motion, in particular spacecraft transfer between two orbits.

1) (adj.) Belonging or pertaining to or of the nature of man or mankind, contrasted with animals.
2) (n.) A human being, → man. See also → anthropo-.

M.E. from M.F. humain, from L. humanus "of man, human," also "humane, kind, gentle, polite," probably related to homo "man," and to humus "earth," on notion of "earthly beings."

Martu, → man, + -gân a suffix forming nouns or adjectives denoting relation and plurality.

1) Any system or mode of thought or action in which human interests, values, and dignity predominate (dictionary.com).
2) Philo.: A variety of ethical theory and practice that emphasizes reason, scientific inquiry, and human fulfillment in the natural world and often rejects the importance of belief in God (dictionary.com).

→ human + → -ism.

A person having a strong interest in or concern for human welfare, values, and dignity (dictionary.com).

→ human + → -ist.

Having concern for or helping to improve the welfare and happiness of people (dictionary.com).

→ humanity + -arian a suffix forming nouns and adjectives, from -ari(us) or -ary + -an.

Martugândust, literally "friend/lover of humanity," from martugân, → humanity, + dust "friend," Mid.Pers. dôst "friend," dôšidan "to love, like, choose;" O.Pers. dauštā- "friend;" Av. zuš- "to take pleasure;" PIE root *geus- "to taste, like, choose;" cf. Skt. jos- "to like, enjoy;" Gk. geuomai, L. gustus "taste, enjoyment" (Cheung 2007).

The study of classical languages and classical literature.

Plural of → humanity.

Martugânik, from martugân, → human, + → -ik, → -ics.

1) All human beings collectively; the human race; humankind.
2) The quality of being human; human nature.

→ human + → -ity.

1) To render humane, kind, or gentle.
2) To make human.

→ human; → -ize.

A person who gives → information.

From → inform + -ant a suffix forming adjectives and nouns from verbs.

The → Zeeman effect obtained in absorption. The phenomenon is observed by sending white light through an absorbing vapor when the latter is subjected to a uniform magnetic field. The laws governing the inverse effect are similar to those for the direct effect.

→ inverse; → Zeeman effect.

A rotating charged black hole. Compare with the → Kerr black hole and the → Reissner-Nordstrom black hole.

Named after Roy P. Kerr and Ezra T. Newman (1929-) who in 1963 independently found this solution to Einstein's → field equations; → black; → hole.

An strong, extended infrared source in the Orion Nebula, about 1 arcminute NW of the Trapezium and about 12 arcseconds south of the → Becklin-Neugebauer object. It dominates the infrared emission at wavelengths above 20 microns. It probably represents a cluster of young and forming stars embedded in a dusty molecular cloud.

Named after Douglas E. Kleinmann (1942-) and Frank J. Low (1933-), who first studied this object in 1967; → nebula.

A region in the sky lying roughly between the → pointer stars of the → Big Dipper that is almost free from → neutral hydrogen gas in the → Galaxy. It is centered at R.A. 10h 45m, Dec. +57° 20', has an area of 15 square degrees, and a → column density of N_{H I} ≤ 5 x 10¹⁸ cm^-2. The Lockman hole is one of the favorite directions for obtaining a clear and unobstructed view of objects in deep space, far beyond our own Galaxy.

Named after Felix J. Lockman et al., 1986, ApJ 302, 432; → hole.

The → Zeeman effect when the emitting source is viewed in the direction of the magnetic field. In the normal longitudinal effect, each spectral line is split into two components with frequencies ν ± Δν. The line with the frequency ν - Δν shows left-hand → circular polarization and that with frequency ν + Δν shows right-hand circular polarization. → transverse Zeeman effect.

→ longitudinal; → Zeeman effect.

The part of the Earth's → mantle extending from about 660 km below the surface to above the → outer core at about 2,900 km.

→ lower; → mantle.

One of the 28 divisions of the sky, identified by the prominent stars in them, that the Moon passes through during its monthly cycle, as used in ancient Chinese, Hindu, and Arab astronomy/astrology.

From O.Fr. mansion, from L. mansionem (nom. mansio) "a staying, a remaining, night quarters, station," from manere "to stay, abide" (Fr. maison, ménage; E. manor, mansion, permanent); cf. Pers. mân "house, home," mândan "to remain, stay, relinquish, leave;" Mid.Pers. mândan "to remain, stay;" O.Pers. mān- "to remain, dwell;" Av. man- "to remain, dwell; to wait;" Gk. menein "to remain;" PIE base *men- "to remain, wait for."

Manzel, from Ar. "dwelling, habitation, mansion."