Archive for March 2012

Trapezium Stars In The Great Orion Nebula

March 2, 2012

Trapezium Sketch -1

Observer’s Challenge complete report:

Theta 1 “The Trapezium”

March 1977:  4 1/4-inch f/10 spherical mirror, Edmund Scientific reflector @ 80x – Beautiful view of all four primary stars.  I could never see the E star with this scope.

February 1993:  10-inch f/4.5 reflector (using 4-inch off-axis stop-down mask) @ 254x – Seeing fair to good.  Could see the “E” star, but not easy. 

12-22-95:  80-mm f/15 refractor – All four stars appear as a beautiful white.

12-23-95:  10-inch f/4.5 reflector @ 120x – Conditions and seeing not good. Could see only the four primary stars.

March 1997:  3.5-inch Maksutov @ 135x – Seeing good, could see four stars.  On one occasion, I thought that I could see the “E” star, but very difficult, using averted vision. 

12-26-99:  10-inch f/4.5 reflector @ 142x – Fair to good.  All six stars visible, E and F fairly easy. 

12-26-99:  4-inch apochromatic f/7 refractor @190x –  Must look carefully to see the “E” star, which appears red.

12-26-99:  4-inch achromatic f/9.8 refractor @ 224x –  Can see fleeting glimpse of “E” star, but not constant.

January 2012:  76-mm Celestron FirstScope; Model 21024 Dobsonian @ 50x –  All four stars visible…nice crisp view. 

January 2012:  100-mm Orion SkyScanner @ 67x – All four stars visible, excellent view…slightly brighter than the 76-mm

02-24-2012:  4-inch f/9.8 refractor @ medium to high power. Seeing fair to poor, could not see E nor F.

02-25-2012:  10-inch f/4.5 reflector @ medium to high power.  Seeing only fair with tube currents, no E or F stars.

Roger Ivester