Fall Asterisms

Use your Scientifics Star and Planet Locator to help you identify these stellar patterns.  Begin by setting it for September 1st.  First and foremost is the huge Summer Triangle (which is a bit of a misnomer since it’s actually best seen in the Fall).   High overhead is the radiant blue-white diamond Vega in the constellation Lyra.  To its east is Deneb in Cygnus.  And due south below these two is the third star in the triangle, Altair in Aquila.  These last two stars are white with a slight bluish cast.  It should be mentioned that one of the brightest part of the Milky Way passes right through the Summer Triangle.


Over in the west we find the Kite in Bootes, anchored by the bright golden-orange  star Arcturus. To its east is the Keystone in Hercules.  Low in the south is the lovely Teapot asterism marking Sagittarius, looking very much like its namesake.  (There’s even steam coming out of its spout—more of the Milky Way star clouds!)  To its east is the Boat of Capricornus.  Above it and well up in the east is one of the sky’s largest asterisms.  This is the Great Square of Pegasus (more of a rectangle than a square.  Some see it as a baseball diamond.)  It encloses a large empty space of sky with no obvious stars within it.  Above it in the north is the House shape of Cepheus.  To its east is the “W” of Cassiopeia.


These are the autumn’s most obvious asterisms.   But there are other less obvious ones but still well worth finding—especially if you enjoy a challenge.  Can you see an Arrow and a Dolphin in the sky just to the east of the Summer Triangle?   They form the tiny constellations of Sagitta and Dephinus, respectively. We began by mentioning Vega in Lyra.  Do you see a Lyre or Harp anchored by the star itself?  And finally, how about the Little Dipper in Ursa Minor pinned to the north celestial pole?  (The Big Dipper mentioned in our intro is visible very low on the northwestern horizon, but is best seen in the Spring sky when it hangs nearly overhead.)


— James Mullaney

Former assistant editor at Sky & Telescope magazine & author of 10 books on stargazing. His latest, Celebrating the Universe!, is available from HayHouse.com.