Sigma Orionis (σ Ori)
Sigma Orionis (σ Ori) is a double star in the constellation Orion, magnitude 3.8.
A multiple star just southwest of Alnitak whose brightest member lights up IC 434, the glow behind the Horsehead. The bright pair σ Ori AB and companion D (magnitudes 3.8 and 6.6) lie 13.5″ apart at PA 84° (measured 2021). E (magnitude 6.3) lies 42″ away and C (magnitude 8.8) 11.4″ away.
When and where to see it
It is best placed in the evening sky around January, when it crosses the meridian at about 10 pm local time (around midnight in December). It can be seen from everywhere south of 87°N and never sets south of 87°S.
At its highest it stands 37° up from 50°N, 52° up from 35°N, 87° up from the equator, 58° up from 35°S.
Facts
- Type
- Double star
- Constellation
- Orion
- Designations
- σ Ori, 48 Ori, 48 Orionis, STF 762, HIP 26549
- Magnitude
- 3.8
- Position
- RA 5h 38.7m, Dec −2° 36′ (J2000)
Open AstroPilot to see when Sigma Orionis (σ Ori) is highest tonight from your location, how easy it is with your telescope or binoculars, and an eyepiece view.