What is rāśi?
The zodiac forms a 360-degree circle divided into twelve rāśis. Each rāśi spans 30 degrees.
Watch the Sun move through twelve equal rāśis.
The Sun’s apparent yearly path makes one circuit through twelve equal 30-degree sections.
The twelve rāśis divide the zodiac into equal parts.
The zodiac follows the ecliptic, the Sun's apparent yearly path across the sky. Dividing 360 degrees by twelve produces twelve equal 30-degree sections. Actual constellations have unequal shapes and boundaries. The rāśis form an equal coordinate grid placed along that starry path.
The broader Sanskrit senses of rāśi include a heap, mass, or collection. In astronomy, it means a zodiacal sign: one equal section of the measured path, with the varied stars forming its background. Nakṣatra names the star-referenced divisions used to locate the Moon in this calendar framework.
Word reference: V. S. Apte, The Practical Sanskrit-English Dictionary · Astronomy reference: International Astronomical Union, zodiac and constellation boundaries
The names of the twelve rāśis
- 1MeṣaAries
- 2VṛṣabhaTaurus
- 3MithunaGemini
- 4KarkaṭaCancer
- 5SiṃhaLeo
- 6KanyāVirgo
- 7TulāLibra
- 8VṛścikaScorpio
- 9DhanusSagittarius
- 10MakaraCapricorn
- 11KumbhaAquarius
- 12MīnaPisces
Indian calendar reference: Government of India, The Indian Calendar
What is the difference between a rāśi and a nakṣatra?
Both measure positions along the same zodiacal path, but they divide the circle in different ways and follow different movements in the calendar.
The zodiac is divided into twelve equal rāśis. In this guide, the Sun’s movement from one rāśi to the next marks each monthly saṅkrānti.
The coordinate method determines a position’s rāśi.
Open Pañcāṅga begins with an astronomical longitude, applies its documented Lahiri (Citrāpakṣa) ayanāṃśa approximation, and then identifies the 30-degree sidereal section containing that position. Another documented ayanāṃśa may place a boundary slightly differently.
Solar entry into a rāśi marks a saṅkrānti.
When the Sun enters the next sidereal rāśi, the calculated crossing is called a saṅkrānti. Open Pañcāṅga may use such a crossing as one documented condition for a cultural or religious event. This guide focuses on the position, boundary, timing, and documented calendar use of the crossing.