nakkhattaṁ

neuter the stars or constellations, a conjunction of the moon with diff. constellations, a lunar mansion or the constellations of the lunar zodiac, figuring also as Names of months & determinant factors of horoscopic and other astrological observation; further a celebration of the beginning of a new month, hence any kind of festival or festivity
■ The recognised number of such lunar mansions is 27, the names of which as given in Sk. sources are the same in Pāli, with the exception of 2 variations (Assayuja for Aśvinī, Satabhisaja for Śatatāraka). enumerated at Abhp. 58–⁠60 as follows Assayuja [Sk. Aśvinī] Bharaṇī, Kattikā, Rohiṇī, Magasiraṃ [Sk. Mṛgaśīrṣa] Addā [Sk. Ārdrā], Punabbasu Phussa [Sk. Puṣya], Asilesā, Maghā, Pubba-phaggunī [Sk. Pūrva-phalgunī). Uttara˚, Hattha, Cittā [Sk Chaitra], Sāti [Svātī], Visākhā, Anurādhā, Jeṭṭhā Mūlaṃ, Pubb-āsāḷha [˚āṣāḍha], Uttar˚, Savaṇa, Dhaniṭṭhā Satabhisaja [Śatatāraka], Pubba-bhaddapadā Uttara˚, Revatī
■ It is to be pointed out that the Niddesa speaks of 28 N. instead of 27 (Mnd.382: aṭṭhavīsati nakkhattāni), a discrepancy which may be accounted by the fact that one N. (the Orion) bore 2 names, viz. Mṛgaśīrṣa & Agrahayanī (see Plunkett; Ancient Calendars etc. p. 227 sq.)
■ Some of these Ns. are more familiar & important than others, & are mentioned more frequently, e.g. Āsāḷha (Āsālhi˚) Ja.i.50 & Uttarāsāḷha Ja.i.63, Ja.i.82; Kattikā & Rohiṇī Snp-a.456
■ nakkhattaṃ; ādisati to augur from the stars, to set the horoscope Mnd.382; oloketi to read the stars to scan the constellations Ja.i.108, Ja.i.253; ghoseti to proclaim (shout out) the new month (cp. Lat. calandae fr. cālāre to call out, scil. mensem), and thereby announce the festivity to be celebrated Ja.i.250; n. ghuṭṭhaṃ Ja.i.50, Ja.i.433; sanghuṭṭhaṃ Pv-a.73; ghositaṃ Vv-a.31 kīḷati to celebrate a (nakkhatta-) festival Ja.i.50, Ja.i.250; Vv-a.63; Dhp-a.i.393 (cp. ˚kīḷā below). n. ositaṃ the festival at an end Ja.i.433
■ nakkhatta (sg.) a constellation Snp.927; collect. the stars Vv.81#1 (cando parivārito). nakkhattāni (pl.) the stars: nakkhattānaṃ mukhaṃ chando (the moon is the most prominent of the lights of night) Thig.143; Vin.i.246 = Snp.569 (but cp. expl. at Snp-a.456: candayogavasena “ajja kattikā ajja Rohiṇī” ti paññāṇato ālokakāraṇato sommabhāvato ca nakkhattānaṃ mukhaṃ cando ti vutto); DN.i.10 (nakkhattānaṃ pathagamanaṃ & uppatha-gamanaṃ a right or wrong course, i.e. a straight ascension or deviation of the stars or planets); DN.ii.259; DN.iii.85, DN.iii.90; AN.iv.86; Thig.143 (nakkhattāni namassantā bālā).