acronical
/əˈkrɑnɪkəl/
adjective
- Relating to the time when a star or planet rises or sets at the same time as the sun.
- An acronical setting occurs when a star disappears below the horizon at sunrise.
- She studied the acronical cycles of the planets for her astronomy project.
- The acronical rising of Sirius marked the start of the ancient Egyptian new year.
Synonyms