The North America Nebula

Stargazers in California wouldn't understand.

The author's 12.5-inch Dob warms up in the Sun on Monday morning so the mirror won't fog up when it's brought indoors.
Tony Flanders
Three good nights back to back, coinciding with a 3-day weekend, at new Moon. It's almost beyond belief!

Columbus Day is pretty much of a non-event in most of the U.S., but most school districts in the Northeast have the day off, making it a 3-day weekend. With weather that's crisp but not cold and the leaves at their most colorful, Columbus Day Weekend is often considered the very best time of all year in this part of the world.

How about getting three deep-sky viewing nights in a row? I estimate that on average, one night in five in New England has suitable weather, with mostly cloudless skies and good transparency. If they happened at random, you'd expect about three 3-night good-weather spells per year. But in fact, weather tends to stay the same for a few days at a time, so the actual number of 3-day good spells per year is probably more. On the other hand, everybody knows that new-Moon periods and weekends are cursed. It's rare enough to get two good weekend nights in a row, much less three!

The downside of last weekend was that I was afflicted by a mysterious illness, whose main symptom were intermittent high fever, headache, and fatigue — so no all-night sessions for me. But that's the beauty of having three nights to play with — I could observe for just a few hours per night and still not feel cheated, as I would if I had only one good-weather night. What a strange experience! I suppose that must be the norm for people who live in dark locations in the semi-arid West — they just take good weather for granted. Not here!

Photo: Robert Gendler; Sketch: Sue French
The highlight of my 3-night observing session was repeating the Deep-Sky Wonders column for October, 2004. (Click on the link in the previous sentence to download the article as a 550-Kb PDF.) The entire article is about a single object — the North America Nebula. This huge nebula is visible only under fairly dark skies, and it looks most impressive through a nebula filter. Many people take an occasional quick look at it, but few take the time to explore it in detail. That's not surprising, because it's easy to get lost in such a huge, complex object.

What you need is a road map — and that's exactly what this article gives you. I had "done" the whole thing before using my 4-inch refractor, but I wanted to repeat the experience with the vastly greater light grasp (though much smaller field of view) of my 12.5-inch Dob.

S&T diagram
What a treat! The key to the article is the complementary presentation in four different forms. There are Sue French's descriptions, a superb pencil sketch also by her, Rob Gendler's photograph, and a detailed star chart.

Sue's sketch is the most accurate depiction of what you see through an eyepiece looking through a nebula filter, but it misses many of the subtle shadings visible in the photo. The photo, on the other hand, has such bright nebulosity that many of the stars are completely obscured — which is where the star chart proves to be handy. And Sue's descriptions tell you what to look for and how to interpret it. Taking it all together, I got many hours of pleasure from the North America Nebula with the aid of this article.

This weekend is forecast to be cloudy, but that's OK. The Moon would make deep-sky observing impossible before midnight anyway, and I already got a good month-long fix last weekend.

One thought on “The North America Nebula

  1. Marc Dubbeldam

    Tony,

    You wrote: “I estimate that on average, one night in five in New England has suitable weather, with mostly cloudless skies and good transparency.”

    And you’re complaining??? In the north-east of England, we would be thanking the Good Lord on our bare knees if we got three decent nights PER YEAR!

    Marc ;-)

COMMENT