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Definición de horario en Greenwich del astro:Definition of the Greenwich Hour Angle (GHA) of a celestial body:
Show the answer
Correct answer: c) The arc of the equator measured from its intersection with the Greenwich upper meridian to the body’s hour circle.
Why it is correct
The Greenwich Hour Angle (GHA / HG) of a celestial body is the arc of the celestial equator measured westward from 0° to 360° from the Greenwich upper meridian to the body’s hour circle.
Why the others are not
- a) It is measured from the Greenwich upper meridian, not the lower meridian.
- b) It is measured along the celestial equator, not the horizon.
- d) Measured from the observer’s upper meridian is the Local Hour Angle (LHA / HL).
How to work it out in the exam
- Greenwich Hour Angle (GHA): equatorial arc from Greenwich upper meridian to the body’s hour circle.
Where this question comes from
- Región de Murcia · 2026 · 1ª convocatoria · CY Tipo 1 · question 10 Official paper · Official answer key
Pending instructor review. Machine translation, not reviewed.