General astronomy

General astronomy

Industry: Astronomy

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General astronomy

achromatic lens

Astronomy; General astronomy

Lens (or combination of lenses) that brings different wavelenghts within a ray of light to a single focus, thus overcoming chromatic aberration. It was first successfully made by Joseph von ...

achromatic objective

Astronomy; General astronomy

A lens of two or more components with different refraction indices (e.g., crown glass and flint glass), used to correct for chromatic aberration.

actinide

Astronomy; General astronomy

Element with atomic number between 89 (Actinium) and 103

actinium

Astronomy; General astronomy

soft, silvery-white, radioactive metal which glows in the dark

active galaxy

Astronomy; General astronomy

1) Active galactic nuclei are very luminous. Their energy output is in two forms: nonthermal continuum and thermal emission line. 2) Any galaxy which is emitting large quantities of non-thermal ...