…continuedObserving Nebulae Season by Season
Three Challenging Autumn Nebulae
Actually, NGC 7000 is difficult to see in most telescopes. With a 5-inch Moonwatch Apogee telescope you should know beforehand what it looks like, and the nebula is downright challenging in a 6-inch f/4. However, a few years ago it was brilliant when I saw it in an 11.4-inch Wright telescope.
The most famous celestial sights have been passed down to us throughout the centuries. There are some objects which, in a sense, belong to the modern amateur. One such object is the Veil Nebula in Cygnus, a broken bubble of luminous gas some 2° in diameter. Although ignored by generations of telescope users, in the last 30 years the Veil has progressed from a difficult test object to a reasonable target for anything from binoculars to the largest amateur telescopes. It's an excellent nebula for training the eye, perhaps the most important observing "accessory," to help us get the most out of the telescope we're using.
Both the east and west arms of this loop are easy in my 20 x 125 Japanese military binoculars. In a 12-inch f/5 telescope the Veil Nebula in Cygnus is beautiful, and so bright that one notes it even when sweeping. But in a 5-inch f/5 the Veil is visible only with difficulty to keen eyes.
The planetary nebula NGC 7293, also known as the Helix Nebula lies in Aquarius about a third of the way from Upsilon (υ) Aquarii to 47. It has a total magnitude of about 6, but its large apparent diameter nearly half that of the Moon spreads the light out and makes it a difficult object visually. I recently saw the Helix Nebula with the 4-inch Clark refractor and was certain that it was glimpsed in a 2-inch finder. Years ago I suggested that readers send me their observations of the Helix Nebula. The bulk of my correspondents indicated that the Helix was more readily seen in binoculars and finders than in telescopes.