Nakshatra
नक्षत्र
A nakshatra is one of 27 lunar mansions that the Moon transits through during its sidereal orbit.
The 27 nakshatras divide the 360-degree sidereal zodiac into segments of 13°20' each. As the Moon moves through its roughly 27.3-day sidereal cycle, it occupies one nakshatra at a time. Each nakshatra has a presiding deity, a ruling planet (in the Vimshottari dasha system), and a distinct nature classified as Dhruva (fixed), Chara (movable), Ugra (fierce), or Mridu (soft), among others.
Nakshatras are central to muhurat (electional astrology). The nakshatra active at a given time determines whether that period is suitable for travel, marriage, business ventures, medical procedures, or spiritual practices. For example, Rohini and Pushya are broadly auspicious, while Bharani and Krittika require more caution. Jyotish practitioners always check the nakshatra before recommending any significant undertaking.
Tithimala determines the current nakshatra by computing the Moon's true sidereal longitude using Swiss Ephemeris, applying the appropriate ayanamsha (precession correction) to convert from tropical to sidereal coordinates. The sidereal longitude is then mapped to the corresponding nakshatra and its quarter (pada). This computation runs in real-time for any given location and moment.
The nakshatra at the time of one's birth is called the Janma Nakshatra and is considered even more important than the Sun sign in Vedic astrology. Daily panchang listings always include the active nakshatra alongside the tithi, yoga, and karana.