Friday, November 20, 2009

Nebulae recently observed

While my favorite objects to observe are galaxies, I also look for nebulae that are in reach of my telescopes wherever they're found. Recently I came across four lesser known examples of planetary and reflection nebulae that can be observed even from fairly hazy and light polluted regions. The first object is NGC-6813, a very small reflection nebula in the constellation Vulpecula. It was almost hidden among the hordes of field stars as a tiny, fuzzy object that would not focus. At 188X it's nebular nature was apparent and it was quite bright. Instead of a circular or oval outline, it had an fuzzy and irregular shape with a star shining within it.

The next object was much larger and easier to pick out from the background stars. NGC-6842 is a large and faint planetary nebula that was not visible until I screwed a O-III filter into the eyepiece. At 103X it was large, about an arc-minute across with no central hole, central star or brighter rim. NGC-6842 is the only other planetary nebula in Vulpecula aside from M-27. Quite featureless but a good test of one's observing skills and sky conditions.

The next objects is the small and quite bright planetary nebula IC-2003 in Perseus. Small and bright, I observed it from my driveway with a 5mm eyepiece and my 10-inch Dob. It was immediately apparent among the surrounding stars with direct vision thanks to the use of an O-III filter while the central star glimmered in the center. This is a surpisingly easy object to observe from the suburbs.

The final object is the tiny and rather elusive planetary nebula IC-351, also located in Perseus. This tiny and round planetary nebula appeared  featureless with no sign of a central star. It was very difficult to locate among the surrounding stars, and required  a magnification of 262X to identify. It was visible without a nebula filter but the use of an O-III made seeing it easier. A good challenge object but not nearly a nice object to observe as M-76 or even IC-2003.

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