Hercules Constellation Facts
hercules constellation
The stick figure like constellation of Hercules is composed mainly of dim stars.
  • Hercules is one of the largest constellations in the night sky but doesn't contain any very bright stars.
  • The constellation is visible in both the Northern and Southern hemispheres.
  • In the Northern hemisphere Hercules can be seen from April to November.
  • In the Southern hemisphere Hercules can be viewed from June to September.
  • In the Southern hemisphere Hercules will appear upside down.
  • The constellation is best viewed away from brightly lit areas, in larger cities only 1 or 2 stars will be visible to the naked eye.
  • Kornephoros which makes up the 'knee' of Hercules is the brightest star in the constellation.
  • Several planets have been detected orbiting stars within the Hercules constellation including an enormous gas giant with 8 times the mass of Jupiter.
  • Hercules is one of the original constellations catalogued by Ptolemy in the 2nd century and is possibly based on earlier Babylonian observations.

Hercules Mythology

Hercules the Hero
An artistic representation of the Greco-Roman mythological hero Hercules.
Hercules is a hero from Greek mythology and his adventures provide the basis for several other constellations. Although he is commonly referred to as Hercules this is actually the Roman translation of his name from the Greek Heracles.
Hercules was an illegitimate child of Zeus, the King of Gods. His mother was Alcmene, wife of the Theban general Amphitryon. Zeus disguised himself as Alcmene's husband in order to bed her, she later gave birth to twins, one of which was Hercules who was fathered by Zeus, the other by her husband. Throughout his life Hercules was taunted by his step-mother Hera, the wife of Zeus, her actions eventually drove Hercules insane which led to him killing his children in a fit of rage. As a way of atoning for his act of madness Hercules was ordered to carry out twelve labors which he eventually completed. As a result of the bravery and courage he had shown throughout his life Hercules became a god upon his death.

Main Stars in the Hercules Constellation
hercules constellation
The number next to each star is its apparent magnitude, its brightness from our point of view on Earth, the lower the number the brighter the star in the night sky.
Zeta
Zeta Herculis is a binary star system around 35 light years from Earth, the primary star has 50% more mass than the sun with a radius around 2 and a half times larger, its companion star is a yellow dwarf similar to our sun.
Sarin
Also known as Delta Herculis, Sarin is a multiple star system located around 75 light years from Earth, the primary star is a white sub-giant with more than twice the radius and mass of our sun.
Kornephoros
Also known as Beta Herculis, Kornephoros is a binary star system around 140 light years from Earth. the primary star is a yellow giant 17 times larger in diameter than our sun.
Rasalgethi
Also known as Alpha Herculis, Rasalgethi is a multiple star system 360 light years from Earth, the primary star in the system is a red giant with a radius almost 400 times greater than the sun.

Finding Hercules - Northern Hemisphere
finding hercules northern hemisphere
The chart shows the position of Hercules over most of the United States in early summer at 9 pm. This chart can also be applied to other areas of the Northern hemisphere such as Canada, the UK and Europe.

In April Hercules will first appear low on the north-eastern horizon around 11 pm before gradually moving higher in the sky, by around 4 am the constellation will be directly overhead before dipping towards the north-western horizon.

From May to August the constellation will be visible from around 10 pm but will appear at different points in the sky depending on the month, in May and June it will first appear in a north-easterly or easterly direction, in July and August it will first appear overhead, before it moves towards the north-western horizon as the night moves on.

From September to November Hercules will first appear in the western night sky between 6 and 9 pm depending on the month, before dipping below the north-western horizon over the next few hours.

Finding Hercules - Southern Hemisphere
finding Hercules southern hemisphere
The chart shows the position of Hercules over most of Australia in early winter at 9 pm. This chart can also be applied to other areas of the Southern hemisphere such as New Zealand, South Africa and South America.

In the Southern hemisphere Hercules is visible in the northern night sky.

In June Hercules becomes visible around 9 pm low on the north-eastern horizon, moving across the night sky towards the north-western horizon over a period of around 6 to 7 hours.
In July and August it will become visible around 6 and 7 pm in the north-eastern sky, moving across the night sky before disappearing below the north-western horizon around midnight.

In September the constellation will appear in the north around 7 pm, gradually moving towards the north-western horizon over the next few hours.