celestial sphere
1
8.4
- noun
- /səˈlɛstʃəl sfɪr/
- Specialized
:
esfera celeste
- A star chart is a diagrammatic representation of the positions of the stars up to a specific magnitude from the whole or a bounded area of the celestial sphere (see figure 1).
Examples
-
The concept of the celestial sphere helps astronomers understand the positions of stars in the night sky.
-
A wobbling Earth makes the North Pole trace out a circle on the celestial sphere.
Blog text (13) -
Both maps project the celestial sphere so that the galactic plane runs horizontally.
Academic text (1996) -
These strips, called sky frames, form a mosaic that will ultimately tile the entire celestial sphere, in an effort known as the Sky Survey.
Academic text (1993) -
This was common practice during the Renaissance, when the same craftsmen made both celestial spheres and Earth globes.
Academic text (2002) -
These systems are necessarily more complex than needed in astronomy, where the celestial sphere is by definition a perfect sphere and the footprints on the sky of practical instruments and data sets are generally simple geometric shapes.
Academic text (2011) -
The number of known radio sources whose extension (projected on the celestial sphere) exceeds 2 million light-years has grown from a handful in the 1970s and 1980s to more than 100 now.
Academic text (2002) -
As we observe the night sky, the celestial sphere appears to rotate around the Earth, revealing different constellations.
-
The diagram clearly illustrates how the celestial sphere represents the apparent motion of the sun and stars overnight.
Synonyms
8
6.8
The imaginary surface around the Earth where stars and planets appear
Surface Forms
Morphology
The meaning is directly compositional: 'celestial' (relating to stars/planets) combined with 'sphere' (a round surface) naturally yields the idea of an imagined spherical heavens. This concept and its lexical components are cross-linguistically common, so a B1 learner who knows both words should be able to infer the MWE's meaning.
Etymology
Celestial sphere comes from an old image used by sky watchers: they pictured a large, invisible sphere around Earth with celestial bodies like stars and planets fixed to its surface. That's why the term is used as a simple 'sky map' to show where objects appear in the sky.