The Trapezium, Theta 1 Orionis

I don’t know about you, but I spent most of my life looking at the nebula, M42 and M43. Untill I completed the Astronomical League’s Double Star Club, I never really paid any attention to this multiple star. At first the challenge was to see all six stars with my 4-inch TV102 refractor. I quickly found that this was not a challenge when there was nice steady seeing even with mediocre transparency. So I have been trying to see how much I could see with smaller instruments.

I have seen all four stars (A,B,C and D) with my Galileoscope, a small 50mm (2-inch) F/10 refractor, using a 20mm Sirius Plossl eyepiece for a magnification of 25x. On January 30th of this year I thought I could see all six stars in the Trapezium using my AT66 refractor and a 5mm Radian eyepiece for a magnification of 80x. Stars A through D were easy with direct vision, while the stars E and F would come in and out of view with averted vision.

Last night, using the same AT66 refractor with a 7mm eyepiece and a 2x barlow for a magnification of 114x, I could see all four of the bright stars in the trapezium with direct vision and a fifth (the F star) with averted vision. I am still looking for that night of perfect seeing where I can see all six stars clearly with the little 2.6-inch refractor.

Here is my sketch from last nights observation.

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