Todays Nakshatra
Nakshatra Today is the second major part of todays Panchanga for Indian vedic time calculations. Nakshatras are 27 twenty seven in numbers spanning accross the 360° bhachakra or zodiac wheel. average span or length of nakshatras is considered to be 13.33° OR 13° 20" kala in the zodiac wheel. Todays Nakshatra can be determined by knowing the current position of moon is in which nakshatra of the zodiac wheel. Suppose today at the time of local Sunrise moon is in Cancersign 10° 30' which lies between Cancersign 03° 20' and Cancersign 16° 40' Which the starting and ending points of Pushya Nakshatra, so Nakshatra Today will be Pushya Nakshatra.
Names of 27 Nakshatras are Ashwini, Bharani, Krittika, Rohini, Mrigashirsha, Ardra, Punarvasu, Pushya, Ashlesha, Magha, Purva Phalguni, Uttara Phalguni, Hasta, Chitra, Swati, Vishakha, Anuradha, Jyeshta, Moola, Purva Ashadha, Uttara Ashadha, Shravana, Dhanishta, Shatabhisha, Purva Bhadrapada, Uttara Bhadrapada &smp; Revati. Some People consider Abhijit as 28th Nakshatra.
The 28th nakshatra is Abhijit Nakshatra, this nakshatra is said to be exist as the last part of Uttarashadha Nakshatra and continues to next Shravan Nakshatra and spans first 4 ghatis in Shravan. So Abhijit spans from Makarsign 06° 40' to Makarsign 10° 53' 20".
Nakshatra Pada or Part
Every Nakshatra is further divided into 4 equal parts, i.e, 13° 20' when divided into 4 parts gives 03° 20' as span of a part. In total there are 27 × 4 = 108 pada in total of all nakshatra, this is the reason why your malas have 108 beads for japa.
Nakshatras are approximately of same duration of a solar day, so the 27 nakshatras are repeated in 27 days and a maasa is usually of 28 days.
There is always 2.25 nakshatras in a rashi of 30° i.e, Two complete nakshatras and one pada/part of 3rd nakshatra.
Nakshatras play a very important roles in forming various important Muhurats and Yogas in the panchangam.
As per the Hindi Panchang Concepts, zodiac wheel is divided into 27 nakshatras, so 360°/27. Each nakshatra has a length of 13° 20'. The first nakshatra, Ashwini, for example, spans from beginning of Meshasign 00° 00' to Meshasign 13° 20'. The second nakshatra, Bharini, spans from Meshasign 13° 20' to Meshasign 26° 40'. The third nakshatra, Kritika, from Meshasign 26° 40' to Vrishsign 10° 00'.