Question

According to the computational method of 'Grahalaghava' for finding the total day-count (Ahargana), by what specific numerical value (the epoch year) is the current Saka year reduced?

• A. Tryabdhindrashakena (1443)
• B. Dvayabdhadrakshakena (1422)
• C. Trinavadrishakena (1493)
• D. Dvayadhishakena (1422)

Hint:

In Karana texts, always look for the 'Saka' year. For Grahalaghava, the magic number is 1442/1443. The mnemonic 'Tri-abdhi-indra' (3-4-14) is a classic way to remember 1443.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
In the Karana category of Indian astronomical texts, the 'epoch' (Kshepaka or Dhruva) is a specific point in time used as a reference to simplify calculations. Instead of calculating from the beginning of the Kalpa or Kali Yuga, which involves astronomically large numbers, a Karana text like Grahalaghava chooses a much more recent date. By doing so, the astronomer only needs to calculate the number of days elapsed since this recent epoch, making the process faster and less prone to manual errors.

Step 2: Key Formula or Approach:
The Grahalaghava, written by Ganesh Daivajna, uses an epoch based on the Saka era. To find the Ahargana for any current date, one must first find the 'Gata-Shaka' (elapsed Saka years) from the text's reference point.
\[ \text{Elapsed Years} = \text{Current Saka Year} - \text{Epoch Year} \]

Step 3: Detailed Explanation:
The Grahalaghava was composed in the year 1520 CE, which corresponds to Saka 1442. However, for the convenience of starting the count from the beginning of the lunar year (Chaitra Shukla Pratipada), the text instructs the practitioner to subtract the value representing the end of the year 1442 or the start of 1443.
- The option 'Tryabdhindrashakena' is a Sanskrit numerical mnemonic.
- Tri = 3, Abdhi = 4, Indra = 14. Reading from right to left (Ankanam Vamato Gatih) or as per the specific code used in the verse: 1443.
- By subtracting 1443 from the current Saka year, the astronomer finds the number of cycles of years that have passed since Ganesh Daivajna's observations. These years are then converted into months and finally into 'Savana' days to form the Ahargana. This reduction is the very first step in the planetary computation of the Grahalaghava tradition.

Step 4: Final Answer:
The current Saka year is reduced by the value 'Tryabdhindrashakena' (1443) to begin the Ahargana process.