Alnilam - ε Orionis (epsilon Orionis)
Alnilam, also designated as ε Orionis (epsilon Orionis), is a variable and double hypergiant star in the constellation of Orion.
Alnilam visual magnitude is 1.7, making it the 28th brightest star in the sky. Thanks to its high brightness, Alnilam is clearly visible when observed from locations with dark skyes, and should be also quite easily visible from light polluted areas.
The table below summarizes the key facts about Alnilam:
Celestial coordinates and finder chart of Alnilam
Alnilam is situated close to the celestial equator, as such, it is at least partly visible from both hemispheres in certain times of the year. Celestial coordinates for the J2000 equinox as well as galactic coordinates of Alnilam are provided in the following table:
The simplified sky map below shows the position of Alnilam in the sky:
Visibility of Alnilam from your location
Digitized Sky Survey image of Alnilam
The image below is a photograph of Alnilam from the Digitized Sky Survey 2 (DSS2 - see the credits section) taken in the red channel. The area of sky represented in the image is 0.5x0.5 degrees (30x30 arcmins). The proper motion of Alnilam is 0.001 arcsec per year in Right Ascension and -0.002 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.
Distance of Alnilam from the Sun and relative movement
Alnilam is distant 1,341.56 light years from the Sun and it is moving far from the Sun at the speed of 26 kilometers per second.
Spectral properties of Alnilam
Alnilam belongs to spectral class B0 and has a luminosity class of I corresponding to a hypergiant star.
The red dot in the diagram below shows where Alnilam is situated in the Hertzsprung–Russell diagram.
Alnilam star system properties
Alnilam is a visual double star which can be observed only with the help of very large telescopes. The table below shows key information about the Alnilam double sysyem: