The Nether-worlds :* Manifestation of the Luminaries - Verse 130

The northern orbit is called NagavithI1 and the southern one is called AjavlthL When the sun rises in the constellations Mula, Purvasadha and Uttarasadha it is called AjavlthL When the sun rises during the rise of the three stars after Abhijit (i.e. Asvini, Bharani and Krttika) it is called Nagavxthi.