Introduction
The third limb of the panchang is the nakshatra. The 360° of the sky is divided into 27 equal parts of 13°20′ each. The Moon crosses roughly one nakshatra a day, so each day has its own nakshatra.
When the panchang says "Rohini today", it means the Moon is moving through Rohini's stretch of sky. The panchang nakshatra is always the Moon's, not the Sun's or any other planet's.
Reading today's nakshatra
The Moon's speed varies a little, so the nakshatra can change at any time of day. A panchang prints the end time with it, for example "Rohini until 2:10 pm, then Mrigashira".
Each nakshatra has 4 padas (quarters) of 3°20′. The nakshatra and pada the Moon held at your birth are your birth nakshatra, and that pada gives the first letter of the name. Each nakshatra has its own page with more detail, such as Rohini, Pushya or Revati.
ePandit's daily panchang shows today's nakshatra and pada for your city.
The muhurta groups
The Muhūrta-cintāmaṇi sorts the nakshatras into groups by nature. When starting something, tradition looks for the group that suits the nature of the task.
- Dhruva / sthira (fixed): Uttara Phalguni, Uttara Ashadha, Uttara Bhadrapada, Rohini. Tradition links them with lasting work, such as laying a foundation or griha pravesh.
- Chara (movable): Swati, Punarvasu, Shravana, Dhanishtha, Shatabhisha. Things that move, such as travel or a vehicle.
- Mridu (gentle): Mrigashira, Revati, Chitra, Anuradha. Gentle things, such as music, art, new clothes, friendship.
- Kshipra (swift): Ashwini, Pushya, Hasta, Abhijit. Things finished quickly, such as starting lessons or trade.
- Mishra (mixed): Krittika, Vishakha. Mixed, everyday work.
- Ugra (forceful): Purva Phalguni, Purva Ashadha, Purva Bhadrapada, Bharani, Magha.
- Tikshna (sharp): Mula, Jyeshtha, Ardra, Ashlesha.
Tradition keeps the ugra and tikshna groups for firm, decisive tasks, and usually picks from the groups above for gentle samskaras. These names classify the nature of a task. They say nothing about a person born in that nakshatra; every birth nakshatra has its own beauty.
Abhijit: the 28th nakshatra
In muhurta work Abhijit is sometimes counted as a 28th nakshatra. It is made from the last pada of Uttara Ashadha and a small opening part of Shravana. Birth charts and dashas use the 27 nakshatras; Abhijit is mainly a muhurta tool. (The midday "Abhijit muhurta" is a different thing: a window of time, not a nakshatra.)
Nakshatras in samskaras
For samskaras such as naamkaran, annaprashan or mundan, tradition usually chooses nakshatras from the dhruva, chara, mridu and kshipra groups. Even so, the nakshatra alone does not fix the day: the tithi, the weekday and the family's own kul tradition are weighed with it. The whole panchang together makes a muhurta.