Magha is nakshatra number 10 of the 27 lunar mansions in Vedic astrology, spanning 120.00° of the zodiac in 13°20' steps. Its planetary lord is Ketu and its presiding deity is Pitrs.
The Moon's position in Magha at birth shapes the Vimshottari Mahadasha sequence — a Magha birth begins life in the Ketu mahadasha, with the balance of that period decided by how far the Moon had travelled through the nakshatra.
Use the free Kundli generator to find whether Magha is your janma nakshatra, and the Panchang to see exactly when the Moon transits Magha on any date.