Indian Astronomy and Vedic Jyotisa

Introduction to Astronomy

• The presentation is on Indian astronomy
• Vinayak Rajat Bhat, Associate Professor, Centre for Indian Knowledge Systems, Chanakya University, Bengaluru, presented the material
• A YouTube link is included for further study

Vedic Era Jyotisa

• Jyotisa, in the Vedic era, was used to understand the seasons for agriculture (sowing and reaping)
• Knowledge of Jyotisa was needed for monthly and seasonal rites
• Specific examples include Darśapūrṇamāsa (new moon and full moon rituals) and Cāturmāsya (seasonal rituals)

Ancient Science in Practice

• Astronomy has been a branch of study from pre-historic times
• All ancient civilizations made methodical observations of the night sky
• Indians have a deep sense of inquiry and curiosity about celestial objects and phenomena

Indian Astronomy: Unique Aspects

• Celestial entities are part of daily life and are interconnected with living beings on Earth
• Astronomy is deeply intertwined with cultural practices and daily life, influencing activities involving events, and scheduling
• "Kālanirnaya" (determination of time) was an important aspect that guided the application of astronomy in everyday life.
• The use of Pancaṅga (calendar) is essential for daily routines

Indian Astronomy: Unique Aspects (continued)

• Indian astronomy is not just an abstract study but a crucial element of daily life
• Ancient Indians developed a systematic approach to studying astronomy, from observation and data collection to analysis.
• This led to the development of advanced mathematics including arithmetic, geometry, algebra, trigonometry, and calculus.

Structure of Jyotisha

• Jyotisa is a three-part systematic structure, similar to a six-part structure
• The components involve various aspects of celestial phenomena including calculations, predictions, and interpretation (Gola, Siddhanta, Ganitam, Nimitta, Muhurta, Jataka, Hora, and Prashna)

Measurement of Time

• Various units for measuring time are discussed with conversion factors
• The presentation includes the definition of different units of time, with equivalent values in seconds.

Units of Time

• Units of time in Indian astronomy are categorized in sections.
• It includes a table including conversion factors
• Human-based units of time and astronomical units are defined.

Indian Calendar: Elements

• The "sidereal period" of an object is the time it takes for an object to complete one revolution against the background of fixed stars.
• The Moon's sidereal period is approximately 27.32 days.
• The zodiac is divided into 27 equal parts called Nakṣatras.
• Each Nakṣatra is associated with a constellation and a specific timing

Indian Calendar: Elements (continued)

• Nakṣatra (asterism) divisions were marked on the ecliptic and are linked to constellations.
• The 27 Nakṣatras are linked to the 12 rāśis (zodiac signs)
• The calendar information maps zodiac signs on the ecliptic.

Illustration of Solstices and Equinoxes

• Solstices occur when the sun's path crosses the extreme points on the Earth's equator
• Equinoxes occur when the sun's path crosses the equator
• The presentation includes diagrams for better understanding of the concept

Indian Calendar: Elements (continued)

• Calendaring is based on the movements of the Sun and the Moon
• A solar year is identified as the time required for the Sun to return to the same star and is the basis of solar calendars.
• Various calendars (e.g., Tripura, Assam, Bengal, Odisha, Tamil Nadu, Kerala, and parts of Punjab and Haryana) are used in different regions

Indian Calendar: Year

• Five systems of the year are outlined in the Vedic corpus, with descriptions for each system (Samvatsara, Idāvatsara, Anuvatsara, Vatsara, Parivatsara)

Solar and Lunar Eclipses

• The presentation describes the concept of solar and lunar eclipses, emphasizing the ancient Indian understanding of their causes (not demon Rahu) and involves a diagram of lunar eclipse components.

Muhurta

• This section identifies auspicious and inauspicious nakshatras and days and presents rules in specific examples.
• Specific details of auspicious /inauspicious nakshatras (stars) are defined in the presentation for consideration.
• Important information for creating a Muhurta for a specific activity is described.

Tarabalam

• A method for predicting auspicious/inauspicious events based on the birth star (janma nakshatra).
• It provides calculation methods and the concept of 'balance of stars'.
• Instructions on calculating Tarabalam, as well as the associated birth nakshatras are provided.

Nakshatras

• An organized list of nakshatras and their corresponding meanings, likely including an auspicious or inauspicious nature of the nakshatra.

Conclusion

• A final message (likely in Sanskrit) given as "Dhanyavaad"