The Lahiri ayanamsha is the most known one in India, it was exactly 23 d 51 m 11 s for epoch 2000 A.D., but the western siderealists consider rather the ayanamsa by Fagan and Bradley which was 24 d 44 m 12 s for epoch 2000 A.D. 
    (Some extremities for epoch 2000: the ’smallest ayanamsa’ was calculated by Raman – 22 d 24 m 25 s – and the ’greatest’ by Larry Ely – 28 d 00 m 13 s.)In a nutshell: like the Tropical ones, there are 12 sidereal signs along 
    the Ecliptic, each having an angular length of 30 arc degrees.