Alnilam
Where is Alnilam?
Look south, about 37° up at 05:17 in Orion. It rises at 23:41 and climbs through the night.
- Rises
- 23:41
- Highest
- 05:38
- Sets
- 11:35
- Best after dark
- 05:17 · 37°
Can I see Alnilam tonight?
From London tonight, Alnilam is above the horizon after dark. It’s highest just before dawn, around 05:17, in the south at 37°.
At magnitude 1.7 it is one of the brighter points in the sky, easy to see by eye when it’s clear.
This is position and timing only: clouds, haze and light pollution aren’t included.
What does Alnilam look like?
Alnilam looks blue-white to the eye. Its spectral type is B0Ia: hot blue-white supergiant (much hotter than the Sun).
Eyes
The middle star in a short, straight row of three bright stars.
Binoculars
The three Belt stars, together with many fainter blue stars, form the Collinder 70 star field, a superb binocular view.
Telescope
A single bright point. The Orion Nebula lies to the south.
About Alnilam
Alnilam is the middle star of Orion’s Belt and the most luminous of the three. It is a blue supergiant, hundreds of thousands of times more luminous than the Sun.
Its name comes from the Arabic for “string of pearls”. Its distance is not well known, but it is the farthest of the Belt stars, well over 1,000 light-years away.
Alnilam is lighting up gas and dust around it, part of the vast star-forming region that also includes the Orion Nebula.
Alnilam is losing mass through a powerful wind from its surface. A star this massive is expected to swell into a red supergiant and eventually explode as a supernova.
Orion’s Belt is known by many names around the world, including the Three Kings and the Three Marys. The three stars lie close to the celestial equator, so the Belt can be seen from almost everywhere on Earth.
Alnilam in Orion
Questions
What are the three stars of Orion’s Belt?
Sources: SkyMate; Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences