Space Lizard Amateur Astronomy Blog

As summer continues, let’s turn our attention back to the “summer triangle.” There aren’t all that many planetary nebulae visible to the backyard astronomer, but one of the better ones can be found in the constellation Vulpecula. The Dumbbell Nebula (M27), discovered by Charles Messier in 1764, was the first planetary nebula discovered. It’s magnitude is a bright (by nebula standards) 7.5, and shows the interesting dumbbell shape that led to it’s name.

Although M27 is in  Vulpecula, the easiest way to find it is to start with the constellation Sagitta. Using your finderscope, scan up from the end of Sagitta and look for an upside down bowl shape (outlined in yellow) with a star in the middle. Point your telecope at that star, and M27 will be right next to it. It’s easy and worth finding.

As we move toward July, warm summer nights bring a wealth of new celestial treasures appearing in the southern skies. One of the finest is the Lagoon Nebula (M8) in the constellation Sagittarius, ofen known as the teapot constellation for it’s obvious central shape. One of only two star forming nebulae just barely visible to the naked eye from northern latitudes, it can be an awe inspiring sight through even a small telescope. An emission nebula roughly 4100 light years away, the Lagoon Nebula shows an amazing amount of detail. A cluster of stars dominates the eastern side of the nebula, while a belt of dusty material seems to divide it nearly in two. Under light polluted skies, only the brigher western side of the nebula may be visible. A nebula filter will help show the nebulosity more prominently, but will also dim the embedded stars.

M8 is an easy nebula to find. Look above the western side of the “teapot”, following a line through the stars at it’s upper left and top. With an apparent magnitude of 6.0, it should be easily visible, and well worth finding on a summer night.

The constellation Lyra, in one corner of the famed “summer triangle”, is home to Messier 57, commonly known as the Ring Nebula. A classic example of a planetary nebula, M57 is not one of the larger or brighter Messier objects. However it is easy to find and, even through a small telescope, lives up to it’s “ring” name. To find M57, start with Vega – a very bright magnitude 0 star at the westernmost corner of the summer triangle. Trailing off to the east of Vega, the shape of the constellation Lyra can be faintly seen. Aim your telescope with a low

power eyepiece about halfway between the two stars at the “bottom” of Lyra. M57 should be visible as a small ring near the center of your field of view. Switching to higher magnification can allow a closer look at the ring structure. Despite a dim magnitude of 8.8, M57 is easily visible and shows a surprising amount of detail, making it a worthy telescopic target. As is common for planetary nebulae, the distance to M57 is difficult to determine. Estimates have ranged from 1000 to 5000 light years, with a current best estimate of around 2300 light years.