36,800
edits
Octans: Difference between revisions
no edit summary
No edit summary |
No edit summary |
||
| Line 2: | Line 2: | ||
Octans is a faint constellation located in the deep southern sky. Its name is Latin for the eighth part of a circle, but it is named after the octant, a navigational instrument. The constellation was devised by French astronomer Nicolas Louis de Lacaille in 1752, and it remains one of the 88 modern constellations. Octans is bordered by seven different constellations, most of which are far more prominent than itself: [[Apus]] (the bird-of-paradise), [[Mensa]] (the table), [[Chamaeleon]] (the chamaeleon), [[Pavo]] (the peacock), [[Indus]] (the Indian), [[Tucana]] (the toucan), and [[Hydrus]] (the male water snake). | Octans is a faint constellation located in the deep southern sky. Its name is Latin for the eighth part of a circle, but it is named after the octant, a navigational instrument. The constellation was devised by French astronomer Nicolas Louis de Lacaille in 1752, and it remains one of the 88 modern constellations. Octans is bordered by seven different constellations, most of which are far more prominent than itself: [[Apus]] (the bird-of-paradise), [[Mensa]] (the table), [[Chamaeleon]] (the chamaeleon), [[Pavo]] (the peacock), [[Indus]] (the Indian), [[Tucana]] (the toucan), and [[Hydrus]] (the male water snake). | ||
Octans is a very faint constellation; its brightest member is Nu Octantis, a spectral class K1 III giant star with an apparent magnitude of 3.73. | Octans is a very faint constellation; its brightest member is Nu Octantis, a spectral class K1 III giant star with an apparent magnitude of 3.73. | ||
==Etymology== | |||
The octant, from Latin octans, is an instrument based on the principle of the sextant (another constellationSextans) but employing only a 45° angle, and used as an aid in navigation. | The octant, from Latin octans, is an instrument based on the principle of the sextant (another constellationSextans) but employing only a 45° angle, and used as an aid in navigation. | ||
The word octant comes from the fact that the instrument's arc covers 1/8th of a circle (=45º). Octans is from the Indo-European root *okto(u)- 'Eight'. Derivatives: eight, octave, octavo, octet, octo-, octad, octopus. [Pokorny okto(u) 775. Watkins] | The word octant comes from the fact that the instrument's arc covers 1/8th of a circle (=45º). Octans is from the Indo-European root *okto(u)- 'Eight'. Derivatives: eight, octave, octavo, octet, octo-, octad, octopus. [Pokorny okto(u) 775. Watkins] | ||