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

An early → B-type star showing helium lines with abnormally large equivalent widths. The surface → chemical abundances of He-strong stars are influenced by the presence of a strong → magnetic field, resulting in a He overabundance that typically varies in strength over the stellar surface. Examples include HR 735, HD 184927, and CPD-62°2124.

→ helium; → strong; → line.

Having an intense, powerful, or vivid effect.
→ strong anthropic principle, → strong arm spiral galaxy, → strong encounter, → strong force, → strong gravitational lensing, → strong interaction, → strong lensing.

O.E. strang "physically powerful, powerful in effect, forceful;" cf. O.N. strangr "strong," Du. streng "strict, rigorous," O.H.G. strang "strong, bold, hard," Ger. streng "strict, rigorous."

Sotorg "large, strong," Mid.Pers. sturg "fierce; gross, coarse," Av. stūra- "strong, large, rough," stāuuišta- "strongest, biggest," cf. Skt. sthūrá- "strong, big, massy, thick," Gk. stylos "column, pillar," M.L.G. stūr "big, strong, coarse."
Zurmand, from zur, → strength, + -mand possession suffix.
Nirumand, from niru, → force + -mand possession suffix.

A version of the → anthropic principle that claims that the → Universe must be suitable for the formation of → intelligent life at some point. Compared with the → weak anthropic principle, this version is very controversial. Its implications are highly speculative from a scientific viewpoint.

→ strong; → anthropic; → principle.

A galaxy with prominent stellar → spiral arms and little star formation between stellar arms, such as M51.

→ strong; → arm; → spiral; → galaxy.

In a star cluster, a → close encounter that strongly changes a star's velocity.

→ strong; → encounter.

The force responsible for holding quarks and gluons together to form protons, neutrons and other particles. It is the strongest of the four fundamental forces. Same as → strong interaction.

→ strong; → force.

A → gravitational lensing phenomenon in which the image distortion is strong enough to be readily recognized, such as in the case of the → Einstein cross or when giant luminous arcs show up in → galaxy clusters (e.g. Abell 2218). Opposite to → weak gravitational lensing.

→ strong; → gravitational; → lensing.

The interaction between quarks that is transmitted by gluons. The characteristic range of the strong interaction is 10^-13 cm, and the time scale over which it operates is on the order of 10^-23 second. Also called → strong force.

→ strong; → interaction.

A situation where the mass concentration in the central regions of → galaxy clusters exceeds the → critical density required for lensing, resulting in multiple images of background objects.

→ strong; → lensing.