An Etymological Dictionary of Astronomy and Astrophysics

The central and brightest of the three stars in → Orion’s Belt and the fourth brightest in the whole of → Orion. Alnilam is a blue-white → supergiant of → spectral type B0 Iae with a → visual magnitude of 1.70 and a → luminosity of 375,000 times the → solar luminosity. It lies at about 1,340 → light-years.

Etymology (EN): Alnilam, from Ar. An-Nizam al-Jawza’ (النظام‌الجوزاء)
“the Orion’s arrangement (of pearls, beads),” from nizam “arrangement” + Jawza’ “Orion”.