Uttara Phalguni is the twelfth nakshatra, straddling the Leo-Virgo boundary from 146 degrees 40 minutes to 160 degrees of the sidereal zodiac, near the star Denebola. Its Vimshottari ruler is the Sun, its presiding deity is Aryaman, god of patronage, contracts, and honourable friendship, and its symbol is the back legs of a bed. Where its pair Purva Phalguni carries the pleasure of union, Uttara Phalguni carries the commitment and the contract that follows, Aryaman presides over the vows of marriage and the bonds of hospitality. Jyotisha reads it as a mansion of stable partnership, generosity, and dependable friendship, classed as Manushya gana. These attributions are the tradition's interpretive layer over the Leo-Virgo border stars that Indian astronomy assigns here.
Uttara Phalguni's padas run through Aries, Taurus, Gemini and Cancer. Aryaman appears in the Rigveda as one of the Adityas specifically overseeing hospitality, contracts and the customs binding host to guest, a narrower and more juridical office than Bhaga's general bestowal of fortune in the paired mansion before it, and this distinction, delight given freely against obligation formally undertaken, is what jyotisha commentators point to in explaining why Purva Phalguni is read for romance and pleasure while Uttara Phalguni is read for the more binding commitment of marriage itself. Denebola, the mansion's associated star, marks the tail of Leo and was itself sometimes read in older Arabic star-lore as an unlucky degree, a separate tradition from the Sanskrit nakshatra doctrine attached to the same point of sky.