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

The part of observing time at a telescope which is not directly used for science, such as the time spent for detector read-out, changing instruments, focusing, etc.

→ over-; → head; → time.

Bâlâ "up, above, high, elevated, height" (variants boland "high, tall, elevated, sublime," borz "height, magnitude" (it occurs also in the name of the mountain chain Alborz), Laki dialect berg "hill, mountain;" Mid.Pers. buland "high;" O.Pers. baršan- "height;" Av. barəz- "high, mount," barezan- "height;" cf. Skt. bhrant- "high;" L. fortis "strong" (Fr. and E. force); O.E. burg, burh "castle, fortified place," from P.Gmc. *burgs "fortress;" Ger. Burg "castle," Goth. baurgs "city," E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg; PIE base *bhergh- "high") + sar, → head.

The second largest satellite of Saturn, also known as Saturn V. It has a diameter of 1530 km and orbits Saturn at a mean distance of 527,040 km in 4.518 days. Rhea is composed primarily of water ice with rock making up less than 1/3 of its mass. It was discovered by Cassini in 1672.

In Gk. mythology Rhea was the sister and wife of Cronus (Saturn) and the mother of Demeter, Hades (Pluto), Hera, Hestia, Poseidon (Neptune), and Zeus (Jupiter).

A vapor that has been heated above its boiling point temperature corresponding to the pressure.

→ super-; → heat; → vapor.

The process in which a liquid is heated to a temperature higher than its boiling point, without boiling. Superheating is achieved by heating a homogeneous substance in a clean container, free of nucleation sites.

→ super-; → heating.