Nakshatra
A nakshatra is one of the 27 lunar mansions, each 13°20′ of the ecliptic, that the Moon passes through in about a day. It sets the day's quality in muhurat and the birth star in a kundali.
What a nakshatra is
The Moon circles the sky in about 27.3 days, so the ancient astronomers divided its path into 27 equal parts of 13 degrees 20 minutes each. Each part is a nakshatra, named after a star or star group that marks it: Ashwini, Bharani, Krittika, Rohini, Mrigashira, and so on to Revati. The nakshatra of the day is the one the Moon occupies at sunrise; the one the Moon occupied at your birth is your janma nakshatra, or birth star.
Each nakshatra is further split into four padas (quarters) of 3°20′. The pada decides the first syllable traditionally used for a child’s name, and the navamsa sign in a birth chart.
Nakshatra in daily life
The panchang lists the nakshatra with the time it ends, because muhurat rules depend on it. Rohini, Mrigashira, Pushya, Uttara Phalguni, Hasta, Chitra, Swati, Anuradha, Uttara Ashadha, Shravana, Dhanishtha, Shatabhisha, Uttara Bhadrapada and Revati are the usual favourable set for new beginnings. Bharani, Krittika, Ardra, Ashlesha, Magha, Vishakha, Jyeshtha, Mula and Purva Bhadrapada are avoided for most events.
Two groups get special treatment: the six Gandmool nakshatras (Ashwini, Ashlesha, Magha, Jyeshtha, Mula, Revati) call for a shanti ritual for a newborn, and the five Panchak nakshatras (Dhanishtha’s second half to Revati) are avoided for certain activities.
Sidereal position and ayanamsa
Nakshatra positions are sidereal: measured from a fixed starting point among the stars rather than from the moving equinox. The offset between the two frames is the ayanamsa, about 24° today. Hastro’s default is Lahiri, the ayanamsa used by the Indian national calendar.
FAQ
How do I find my birth nakshatra?
Enter your birth date, time and place in the Kundali tab. The Moon’s sidereal longitude at that moment gives the nakshatra and pada.
Why does a nakshatra last about a day?
The Moon moves roughly 13° a day against the stars, and each nakshatra is 13°20′ wide, so the Moon spends a little more than a day in each.
Is Abhijit a nakshatra?
In the 28-nakshatra scheme Abhijit sits between Uttara Ashadha and Shravana. The daily panchang uses 27, but the Abhijit muhurat, the eighth muhurta around midday, keeps the name.
Related: Tithi Yoga (panchang) Kundali (birth chart) Gandmool nakshatra Panchak