The Sky in September

September Constellations & Folklore

By Francine Jackson
At this time of year, even though the season of summer ends this month and fall begins, the sky takes a little longer to shift to its next season. The Summer Triangle is still in a beautiful observing position, not really giving the fall constellations a chance to come to full view. So, while we’re waiting, it might be good to turn back to the north and see what is happening there.

Observing Projects for September

Some Bright Autumn Double Stars

: By Glenn Chaple
Autumn is a season of promise for the stargazers. The nights are getting longer, the air clearer, and those pesky summer mosquitoes are a thing of the past. In a few months, Orion and his magnificent wintry retinue will take center stage. While the autumn night sky appears devoid of bright stars, it’s still home to a rich array of double stars. Here are ten of the best:

Some Bright Summer Double Stars

: By Glenn Chaple
In this modern era of the huge galaxy-gulping Dobsonian reflector, double stars have become the neglected children of the cosmos. That’s too bad, because few heavenly objects have the visual appeal of double stars.

A Selection of Double Stars in Draco

: By Glenn Chaple
A hazy summer evening may prevent you from observing nebulae and galaxies, but it could afford ideal seeing conditions for high power targets like double stars.

A Selection of Double Stars in Andromeda

: By Glenn Chaple
Andromeda is home to a fine collection of double stars. Here are eight of the best. Data on magnitudes and separation were taken from the Washington Double Star Catalog.
Mizar, The First Double Star

Mizar, The First Double Star

: By Glenn Chaple
The middle star in the handle of the Big Dipper, Mizar is the easiest double star for the novice to locate. It boasts historical importance as the first double star discovered.

Chaple’s Arc

: By Glenn Chaple
Forgive me for the apparent ego trip, but this month I’m going to introduce you to an amazing little asterism called “Chaple’s Arc.” I stumbled upon the Arc in the mid-1970s while looking for the double star h1470.

Epsilon Pegasi: The Pendulum Star

: By Glenn Chaple
Epsilon Pegasi (Enif) is an optical double star comprised of magnitude 2.5 and 8.7 component stars separated by 144 seconds of arc. Pairs this wide usually don’t merit much consideration, but wait! Epsilon Pegasi has a surprise for us.

Izar (ε Boötis)

: By Glenn Chaple
A larger telescope and magnifying power of 200X will readily split Izar and reveal a striking color contrast between the golden yellow primary and its bluish companion. The Russian astronomer Wilhelm Struve, who conducted a double star survey in the late 1820s and early 1830s, nick-named it “Pulcherrima” (The Most Beautiful).

Almach

: By Glenn Chaple
Last month, I suggested that our featured object, Albireo, may not be the most beautiful double star in the sky and I’d introduce a rival this month. If you guessed that Albireo’s challenger is Almach, the gamma (?) star in Andromeda, you’d be correct!

Struve 2816 and 2819: Triple and Double Stars in Cepheus

: By Glenn Chaple
There’s something hypnotic about a double star – two gleaming points of light shining bravely through the surrounding darkness. A triple star is even more mesmerizing. Place a double star and triple star in the same eyepiece field, and the visual effect is stunning. This is what greets the eye when you view the triple/double star combo Struve 2816 and Struve 2819.

Resources

Eyes on the Sky

Eyes on the Sky makes it easier for anyone to find objects in the night sky and/or learn how to use astronomy equipment, and educates about smarter lighting practices. Take a look at the weekly videos to learn what YOU can find in the night sky, this week - naked eye, binocular and telescopic objects are always discussed, so anyone can look up and see planets, stars and other deep sky objects.

SkyMaps.com

An astronomy webstore where you can doanload a free sky map each month to explore, learn and enjoy the night sky

Uncle Al's Starwheels

Learn to identify the constellations by printing and building this simple planisphere.