Constellation Equuleus (Little Horse)

Equuleus: IAU Constellation Map [150]


Equuleus is the second smallest constellation in the sky with 72 square degrees and is not particularly noticeable. It is east of Delphinus, right next to the head of Pegasus. The center of the constellation culminates around midnight on August 9th. [9, 15]

Stars with Proper Names [154]
α Equ Kitalpha, Kitel Phard, Kitalphar
Data for constellation Equuleus [150]
IAU NameEquuleus
IAU GenitiveEquulei
IAU Abbr.Equ
English NameLittle Horse
Opposition7 August
Season (47° N)June … November
Right Ascension20h 56m 11s … 21h 26m 20s
Declination+02° 28' 38" … +13° 02' 21"
Area72 deg2
Neighbours (N↻)Peg, Del, Aqr


Constellation Equuleus
Constellation Equuleus: Illustration from «Uranometria» by Johann Bayer, copper engraving by Alexander Mair, 1603 [28]

Mythology and History

It is said of this constellation that Hipparchus was born in 150 BC. Was formed from a few faint stars near Delphinus. Around three centuries later, Ptolemy summarized the constellation of four stars in his Almagest.

Although Equuleus is a small and faint constellation, it is associated with the legend of the first horse. A well-known Greek myth tells of a city that was looking for a name. Zeus, the king of the gods, decided that the city should be named either after Poseidon, the fierce god of the oceans, or after Athena, the goddess of wisdom. His final decision would be based on the gift the two gods gave the city. Poseidon's gift was a horse that he sculpted from the foam of the ocean waves. The first horse was a wonderful creature, but this gift from Poseidon - also known for his sudden, cruel fits of anger - was also considered a symbol of war. Then Athena came out and showed her present. It was an olive tree, which (then as now) was considered a symbol of peace. So the goddess won the competition and the city - known for her peace, wisdom and the arts - was named Athens. [55]

According to another interpretation, it is said to be Celeris, the brother of Pegasus, who is represented by the neighboring constellation. [7] According to another interpretation, it was a gift from Hermes (Mercury) to Castor. [10, 25]


  • [9] «Drehbare Sternkarte SIRIUS» von H. Suter-Haug; Hallwag-Verlag, Bern
  • [10] «dtv-Atlas zur Astronomie» von Joachim Herrmann; Deutscher Taschenbuch Verlag; ISBN 3-423-03006-2
  • [15] «Hartung's Astronomical Objects for Southern Telescopes» by David Malin and David J. Frew; Melbourne University Press 1995; ISBN 0-522-84553-3
  • [25] «Das Taschenbuch vom Sternenhimmel» von Peter von Eynern; Wilhelm Heyne Verlag, München, 1972
  • [28] «Uranometria omnium asterismorum continens schemata, nova methodo delineata aereis laminis expressa» Johann Bayer, Augsburg, 1603; DOI:10.3931/e-rara-309
  • [55] Eye On The Sky: Delphinus, Equuleus by Deborah Byrd; Astronomy 10/92, p.48
  • [150] IAU: The Constellations, 11. Oktober 2020;
  • [154] Yale Bright Star Catalog, 15. Oktober 2020;