Alnilam
DSS image of Alnilam
Overlaid DSS image of Alnilam, 60' x 60' with north at top and west to the right

Aladin viewer for the region around Alnilam
Epsilon Orionis, ε Ori, 46 Ori
BD-01 969, HD 37128, HR 1903, WDS J05362-0112, SAO 132346, HIP 26311

Type  Star
Magnitude  1.69
Right Ascension  5h 36' 12.8"  (2000)
Declination  1° 12' 7" S
Constellation  Orion
Classification  B0Ia
Observing Notes

Andrew Cooper
Nov 25, 2020    Waikoloa, HI (map)
20cm f/6 Newtonian, Cave Astrola @ 76x
Seeing: 5 Transparency: 6 Moon: 0%

Brilliant blue-white, no companion noted, in a lovely field scattered with 7 to 9th magnitude stars

Captain William Henry Smyth
Jan 8, 1835    No. 6 The Crescent, Bedford, England (map)
150mm f/17.6 refractor by Tully 1827

A standard Greenwich star, in the centre of Orion's belt, with a distant companion. A 2½, bright white, and nebulous; B 10, pale blue. This fine star, rated a full second magnitude by Flamsteed, is in a neat trapezium of the 8th magnitude, in a rich vicinity. It is often called Alnilam, from the Arabic Al-Nidhám, or Nizám, the string of pearls, in allusion to its situation between ζ and δ, forming, as Robert Recorde says, the bullions set in Orion's girdle. It may assist the alignment of the vicinity to state, that the belt extends exactly 3°, or 1½° on each side of this star.

As neither ζ nor δ could have offered much peculiarity to Padre de Rheita's binocular telescope in 1643, the treble-bodied star which he saw in or near Orion's belt, may have been ε or σ, "in aut propè cingulum Orionis vidisse se tricorpoream stellam." The worthy Bohemian's visions and views sadly interfere with the exactness of his real discoveries in cælo stellifero. The galley-poet tells us:
Our Lady's wand is bless'd by all
who watch those gems on high,
And centre of that brilliant zone
epsilon meets the eye.
The attractions of this beautiful constellation have thus afforded five objects in close succession; and numerous others deck this comparatively compact region. It is a wonderful spot; and there is food for the theorist in the brilliant oblique zone exhibited by Taurus and Orion, coming to a full stop at Sirius.
― A Cycle of Celestial Objects Vol II, The Bedford Catalogue, William Henry Smyth, 1844
Other Data Sources for Alnilam
Associated objects for Alnilam
Nearby objects for Alnilam
Credits...

Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.

A complete list of credits and sources can be found on the about page

Alnilam