|M42 "Orion Nebula" & M43: Emission Nebulae (Orion) RA: 05h 35.0m / DEC: -05° 25'.0|
Instrument: 10-inch Starfinder
M42, The Orion Nebula, is arguably the greatest celestial treasure available to observers in mid-northern latitudes. You will find it in the hilt of Orion's sword just a few degrees below the three, bright belt stars. It's an easy naked eye object under typical suburban skies. The sketch at left is based on a 36X view in my 10-inch equatorial mount Newtonian. M42 spans 70'x40', more than twice the size of the full Moon. It features expansive wings sweeping east and west. These give the nebula the appearance of an open Chinese fan. The Fish Mouth can be seen as a dark notch in the underside of the nebula. M42 shows a distinct green hue under excellent observing conditions. Messier 43, the nebulous comma patch surrounding the 7th magnitude star immediately to the North, dangles from M42 like an ornament. Observers with large aperture should seek out the nearby Rosette Nebula, an equally stunning gem of the winter sky.
The Orion Nebula owes its grand appearance to a grouping of four young, hot stars known collectively as the Trapezium. These are located south of the Fish Mouth. The brightest member produces enough radiation to cause the surrounding shell of hydrogen gas to glow so brightly that we can see it from a distance of 1,600 light-years. My sketch at right, based on a 190X view, only begins to capture the intricacy of detail visible with moderate aperture. But it provides the clearest evidence that one of the most widely held opinions in deep-sky observing is no more than a myth. It is often said that deep-sky observing is best done using low powers. Poppycock! Low power is great for finding objects and, if the seeing is terrible, may sometimes provide the best view. But a magnification producing a 1-mm to 2-mm exit pupil will often be your best view.
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Revised: February 10, 2002 [WDF]