Zeta Orionis (Struve 774)

October 12, 2006: To help provide a consistent style for my double star sketches, the above sketch is a digital update to the original sketch.

Observation Notes:

My first impression was of a wide double with a blue southern component that was much brighter than its southern counterpart. I had to use averted vision to see the northern star–high clouds were getting very problematic. After further research later, it turns out I missed a third bright component that is separated by 2.4″ from the brightest star. So I should really be seeing a triple star. I want to look at this again to see if I can pick out this closer star.

Subject Zeta Orionis (Alnitak / 50 ORI / STF 774)
Classification Multiple Star
Position Orion [RA: 05:40:45.5 / Dec: -01:56:33]*
Separation* 2.4″, 58″
Magnitudes* 1.9 / 4.0 / 9.9
Position Angle* 162° / 10°
Date/Time 01/16/05 – 10:05 PM
Observing Loc. Flagstaff, AZ – Home
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 10 mm + 2X Barlow (240X)
Conditions Patchy high clouds, cool (34°F), 1st quarter Moon

Seeing 5/10
Transparency Mag 4.0 NELM

*Based on published data.