Seasonal Doubles (Summer's Close Pairs)

July to October is the season for the Summer Constellations in the Northern Hemisphere.  There are 17 Summer Constellations and they are located between 18 hours and 0 hours Right Ascension.  A list of close doubles in these constellations can be found here.

Aquarius (Aqr) The Water Bearer
Aquila (Aql) The Eagle
Capricornus (Cap) The Sea Goat
Cepheus (Cep) Cepheus, King of Ethiopia
Corona Australis (CrA) The Southern Crown
Coronas Borealis (CrB) The Northern Crown
Cygnus (Cyg) The Swan
Delphinus (Del) The Dolphin
Equuleus (Equ) Little Horse
Lacerta (Lac) The Lizard
Lyra (Lyr) The Harp
Pegasus (Peg) The Winged Horse
Piscis Austrinus (PsA) The Southern Fish
Sagitta (Sge) The Arrow
Sagittarius (Sgr) The Archer
Scutum (Sct) The Shield
Vulpecula (Vul) The Fox

Seasonal Doubles (Spring's Close Pairs)

Spring, in the Northern Hemisphere, runs from April until July.  There are 15 constellations that dominate the skies during this season.  They fall between 12 hours and 18 hours Right Ascension.  The lists for these constellations are like the previous ones - the apparent magnitude for the primary cannot be dimmer than 8.9v, the delta-m is 0-2m and the separation is limited to between 1 and 2 arc seconds.  The lists can be found here.

Boötes (Boo) The Plowman
Canes Venatici (CVn) The Hunting Dogs
Coma Berenices (Com) Berenice's Hair
Corvus (Crv) The Crow
Draco (Dra) The Dragon
Hercules (Her) Hercules, son of Zeus
Libra (Lib) The Scales
Lupus (Lup) The Wolf
Ophiuchus (Oph) The Serpent Bearer
Scorpius (Sco) The Scorpion
Serpens Caput (Ser) The Serpent's Head
Serpens Cauda (Ser) The Serpent's Tail
Ursa Major (UMa) The Great Bear
Ursa Minor (UMi) The Little Bear
Virgo (Vir) The Maiden

The constellation Serpens is noted for being the only one to consist of two separate areas of the sky.  These two areas make up the Serpent's head (to the west) and the tail (to the east).  The Serpent Bearer, Ophiuchus, is positioned between the two parts of Serpens.  In ancient renditions of the constellations, Serpens is typically shown as being held behind Ophiuchus, thus the separation.