Alnilam

Alnilam is a blue supergiant of spectral type B0Ia, the middle and brightest star of Orion's Belt at magnitude 1.70. Located about 2,000 light-years from Earth, it is one of the most distant bright stars visible to the naked eye. Alnilam is extraordinarily luminous — roughly 275,000 times the luminosity of the Sun — and has about 40 times the Sun's mass. It is losing mass rapidly through powerful stellar winds.

Alnilam is the middle star of Orion's famous Belt, flanked by Alnitak to the east and Mintaka to the west. The three Belt stars are one of the most recognizable patterns in the night sky. Through binoculars, the surrounding region is rich with nebulosity — the emission nebula NGC 1990 surrounds Alnilam itself. The Belt points downward to Sirius and upward to Aldebaran, making it an excellent starting point for star-hopping. Best observed from November through March.

The name Alnilam comes from the Arabic 'al-Nilam' meaning 'string of pearls,' referring to the line of Belt stars. Orion's Belt is one of the most universally recognized star patterns across human cultures — it has been identified with three kings, three sisters, a celestial bridge, and many other mythological figures worldwide. The ancient Egyptians aligned the three Great Pyramids of Giza to mirror the Belt stars.