Monthly Messier Star-Hop; August #2
By Art Russell

The first fresh breaths of the coming Fall season have already been felt in Atlanta, heralding clear skies and the much awaited departure of our ever present summer haze and humidity. This comes with mixed blessings in that it typically also means the departure of some of the more striking deep sky wonders located in our southern skies as the constellations of Scorpius, Ophiuchus, Sagittarius and Scutum draw ever closer to the western horizon. However, there is still time just after dark to get a good look at a few of these interesting objects. This month we'll take a look at four of them: the globular clusters M55 and M75 in Sagittarius, and the open clusters M11 and M26 in Scutum, astride the summer Milky Way.

As with all deepsky astronomy, you'll want to head for the darkest possible skies. This month's objects can be located from the constellation Sagittarius. Get yourself properly oriented by locating Sagittarius' "Teapot", about 30 degrees (about one and a half times the distance spanned by your thumb and little finger spread against the night sky at arms length) or a bit more from the southern horizon. It is there that we begin our star-hops.

Star-Hop #1; M75, NGC 6864. This is our toughest target for this month. Of all of Messier's cataloged globular clusters, this is probably the one I had the most difficulty finding. It is located almost by itself in the middle of a relatively dim star-field. Finding it will take a bit of perseverance. However, you'll be glad if you do as you'll be rewarded with a small, but very rich globular cluster, and will have enhanced your ability to star-hop as well.

Beginning in the "Teapot": Locate the star Phi Sagittari. Extend an imaginary line from Phi Sagittari east-northeast past the star Sigma Sagittari to the star Psi Sagittari, a distance of a little less than 7 degrees, or about the distance spanned by your 4 fingers held together at arm's length against the night sky. From there, continue the line in the same direction for another 12 degrees, or a bit more than the distance spanned by your fist held at arm's length against the night sky. Scan this area with your telescope at low power, or a set of binoculars and you should find the dim haze of M75. This cluster will handle magnification well, so take the time to examine it with your highest power eyepiece. You'll be glad you did as you find hints of apparent lanes throughout this globular cluster. While you are in the area, scan about 2 and a half degrees northwest (about the distance spanned by 2 fingers held together at arm's length against the night sky) and search for small, dim, bluish disk, the planet Neptune! You won't be able to see any details, but you will be looking at one of the gas giants of our outer solar system.

Star-Hop #2; M55, NGC 6809. Locating the globular cluster M55 is considerably easier than M75 as it is located just to the southeast of the "Teapot."

Beginning in the "Teapot": Locate the star Lambda Sagittari, and extend a line to Phi Sagittari, a distance of about 4 degrees. Using this distance as a scale, extend your line from Lambda Sagittari, past Phi Sagittari for a little more than 16 degrees (4 X the distance between Lambda and Phi Sagittari), or a little more than the distance spanned by your index and little fingers spread against the night sky at arm's length. Search this area with a pair of binoculars or a telescope at low power and M55 should be visible as a moderately bright, but not well concentrated globular cluster.

Star-Hop #3; M26, NGC 6694. Locating the open clusters M26 and M11 takes us out of Sagittarius and into the constellation Scutum and the summer Milky Way. Take time to wander about the Milky Way. You'll find uncounted numbers of stars here, as well as open clusters, nebula and planetary nebula in abundance.

Beginning in the "Teapot": Locate the star Epsilon Sagittari, and extend a line to the star Lambda Sagittari, a distance of about 9 degrees. From here, extend the line a little east of due north for about 17 degrees or a little less than twice the distance between Epsilon and Lambda Sagittari. Here you'll find the bright star Alpha Scuti which is often lost in the myriad stars of the summer Milky Way and the Scutum Star Cloud. Locate M26 from Alpha Scuti by scanning to the southeast for a distance of only a little less than 3 degrees, or about the distance spanned by 2 fingers held together against the night sky at arm's length. You'll notice M26 as a loosely concentrated grouping of stars, which at moderate power may resemble a flattened "Star of David" in appearance.

Star-Hop #4; M11, NGC 6705, "The Wild Duck Cluster." Our last object for this month is probably the most attractive of the month. As its name suggests, this open cluster has often been compared to a flight of wild ducks. Take a look. What does it remind you of?

Beginning at Alpha Scuti: Extend a line about 4 and a half degrees, a little less than the distance spanned by 3 fingers held together against the night sky at arm's length, to the northeast, to find the star Beta Scuti. M11 is located less than 2 degrees, about twice the distance spanned by your little finger against the night sky at arm's length, to the southeast. Binoculars and telescopes at high power will immediately reveal this splendid and bright cluster against the rich background of stars in the Milky Way. Take your time here. You'll enjoy the show!