General astronomy

General astronomy

Contributors in General astronomy

General astronomy

(variable star): a type of variable star that changes brightness by changing size and temperature with a period that depends on its average luminosity. More luminous Cepheids have longer pulsation ...

chondrule

Astronomy; General astronomy

round glassy structure 0.5 to 5 millimeters in diameter embedded in a primitive stone meteorite. It is a solidified droplet of matter from the early solar nebula and is the very oldest part of the ...

chromatic aberration

Astronomy; General astronomy

a defect in the images from refractor telescopes that is caused by different colors of light focussing to different points behind the glass lens. A rainbow of colors is produced around the image.

circumpolar

Astronomy; General astronomy

when an object is close enough to either the north celestial pole or south celestial pole (within an angular distance = observer's latitude) such that the object never moves below an observer's ...

microquasar

Astronomy; General astronomy

Microquasars are stellar mass black holes, that display characteristics of the supermassive black holes found at the centers of some galaxies. For instance, they have radio jets - something not every ...

extinction

Astronomy; General astronomy

reduction in the intensity of the light (the number of photons) from a celestial body as the light passes through a dust cloud. Dust clouds in space make stars behind the dust clouds appear dimmer ...

extremophile

Astronomy; General astronomy

living organism that survives (even thrives) in extreme environments such as very hot or very cold temperatures, very acidic or very basic conditions, or very high pressures.