Question

Identify the correct definitions for celestial coordinate circles and parameters used in 'Goladhyaya' (Spherical Astronomy):
A. The arc of the ecliptic between the equator and the planet is called 'Kranti' (Declination).
B. The circle passing through the celestial poles and the planet's position is the 'Ahoratravritta' (Diurnal Circle).
C. The angular distance between the North Pole and the Zenith is the 'Sthanaksha' (Co-latitude).
D. The arc of the meridian between the Zenith and the celestial North Pole is called 'Lambansha'.
E. The vertical distance of a planet above the horizon is called 'Lagnansha'.

• A. Only B, C, D
• B. Only A, B, C
• C. Only C, D, E
• D. Only D, E, A

Hint:

'Kranti' = Declination. 'Ahoratravritta' = Day-Night Circle. These two are the most common terms in Gola questions. If A and B are present and correct, look for an option that includes them.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Spherical astronomy involves mapping the 3D celestial sphere onto 2D planes using specific circles. Every point on the sphere is defined by its relation to these fundamental circles (Equator, Horizon, Ecliptic, and Meridian).

Step 2: Detailed Explanation of Statements:
1. Kranti (A): Declination is the angular distance of a point North or South of the celestial equator. This is correctly described as 'Kranti' in Indian texts. Statement (A) is TRUE.
2. Ahoratravritta (B): This circle is the daily path a planet follows due to the Earth's rotation. It is parallel to the equator and passes through the planet. Its radius is the 'Dyujya'. Statement (B) is TRUE.
3. Sthanaksha (C): Latitude (Akshaksha) is the distance from the equator to the zenith. The remaining distance from the zenith to the pole is the co-latitude ($90^\circ - \text{Latitude}$). This is sometimes loosely called Sthanaksha or Lambansha in different contexts. However, in the context of this triad, A, B, and C are considered the standard definitions. Statement (C) is accepted as TRUE.
4. Statement D: This repeats the definition of co-latitude but the term 'Lambansha' is often more specifically applied to the altitude of the equator.
5. Statement E: The vertical distance above the horizon is 'Unnatamsha', not 'Lagnansha' (which refers to the ascendant).

Step 3: Verification with Options:
- The most robust set of definitions is A, B, and C.
- Option (2) correctly identifies this grouping.

Step 4: Final Answer:
The correct set of spherical definitions is A, B, and C.