Leo Constellation

leo constellation

   Leo is one of the oldest recorded constellations, it was percieved as a lion by ancient civilizations as far back as 6,000 years ago. Mesopotamians are known to have documented the “lion” constellation. 

   It is the 12th largest constellation in size, occupying an area of 947 square degrees.


   Leo is a highly recognizable constellation, as it is one of the few constellations that resemble its namesake. It is fairly easy to find because the “pointer stars” of the Big Dipper point to Leo. It contains several bright stars making it one the most easily recognizable constellations in the night sky.

   The constellation is visible in both the Northern and Southern hemispheres. In the Northern hemisphere the constellation can be seen from January to June. In the Southern hemisphere Leo can be viewed in the summer and autumn months and will also appear upside down.

   Leo is located in the second quadrant of the northern hemisphere and can be seen at latitudes between +90° and -65°. It lies between Virgo and Cancer. Other neighboring constell-ations are Coma Berenices, Crater, Hydra, Leo Minor, Lynx, Sextans and Ursa Major.


   The constellation is home to the bright stars Regulus and Denebola, the nearby star Wolf 359, and to a number of famous deep sky objects, among them galaxies Messier 65, Messier 66, Messier 95, Messier 96, Messier 105, NGC 3628 and Leo Ring.

   The brightest star in constellation Leo is Regulus. Seventy five times bigger than the Sun, it is located at a distance of 83 light years from our planet. Its name means “prince” or “little king.”  Regulus is 150 times brighter than the Sun, and its energy output is 350 times that of the latter.

   Denebola is the second brightest star in Leo and the 61st brightest star in the sky. It is approximately 35.9 light years distant from Earth. The star can easily be seen without binoculars. Denebola has 75% more mass than the Sun, 173% of the solar radius, and is 12 times more luminous. It is a relatively young star. Its estimated age is less than 400 million years. 

   Wolf 359 is a red dwarf and is only 7.78 light years distant. Despite its proximity to the Sun, Wolf 359 can only be seen through a large telescope. It is one of the lowest-mass stars ever discovered, as well as one of the faintest. It emits only about 0.1% of the Sun’s energy, has 8% of the Sun’s mass, and only 16% the solar radius. The star has an estimated age of less than a billion years. Wolf 359 is classified as a flare star, one that can undergo dramatic increases in luminosity for several minutes as a result of magnetic activity on its surface. The flares from the star emit strong bursts of gamma rays and X-ray radiation.

   Messier 65 is an intermediate spiral galaxy in Leo and is approximately 35 million light years distant. The galaxy does not contain much dust and gas and there isn’t much star formation occurring in it. Most of the stars in the galaxy are old.

   Messier 66 is an intermediate spiral galaxy in Leo. It is about 36 million light years distant. M66 is approximately 95,000 light years across and notable for its dust lanes and bright star clusters. It is part of the Leo Triplet, along with M65 and NGC 3628.

   Messier 95 is a barred spiral galaxy in Leo. It is approximately 38 million light years distant. The central region of M95 has a ring-shaped starburst region around the core with a diameter spanning about 2,000 light years. M95 belongs to the M96 Group of galaxies, which also includes M96 and M105, and also at least nine other galaxies. A supernova was observed in M95 in March 2012.

   Messier 96 is another intermediate spiral galaxy in Leo constellation. It is about 31 million light years distant. M96 is the brightest galaxy in the M96 Group. The galaxy is classified as a double-barred spiral with a small inner bulge through the centre along with an outer bulge. Ultraviolet emissions from the galaxy’s central region suggest that it has a super-massive black hole at its core.

   Messier 105 is an elliptical galaxy in Leo. It is approximately 32 million light years distant. The galaxy is known to have a super-massive black hole at its center.

   GC 3628 is an unbarred spiral galaxy approximately 35 million light years distant from the solar system. The galaxy is notable for having a long tidal tail spanning about 300,000 light years, and a broad, obscuring dust band along the outer edge of its spiral arms. Along with Messier 65 and Messier 66, NGC 3628 forms the Leo Triplet galaxy group.

   Leo Ring is an enormous primordial cloud of hydrogen and helium found in orbit of two galaxies in the Leo constellation, which is believed to be a left over from the Big Bang.



   While there are many different versions of the constellation myth of Leo, it is nonetheless one of the most popular constellations through its many stories. The most common version of the story is told in Greek Mythology attributing to the ancient story of Hercules and his 12 trials.

   Much like any hero, Hercules was born with having a God for a father- Zeus. Hercules was the illegitimate son of Zeus and a Greek mortal woman named Alcmena. Alcmena named the baby, Hercules, which in Greek translates as “glorious gift of Hera.”  While Zeus’s queen, Hera, slept, Zeus had his child feed from her breast therefore making him immortal. After discovering this, Hera became jealous and tried to kill Hercules, but failed. 

   Hera’s outrage never died. Years later after Hercules had a family, she cast a spell over him so he lost his mind and murdered his wife and children. Once the spell was broken, Hercules was devastated and sought penance from the oracle at Delphi. Hercules was sent to serve as a slave to King Eurystheus of Tiryns and in order to make amends for his crime, the King sentenced him to complete 12 trials.

   Hercules’ first trial was to find and kill the Nemean Lion. According to Greek mythology, Leo was a ferocious lion who fell to the earth in the forests of Nemaea. He feasted on the animals of the forest and also caught and ate many human beings. Many brave men lost their lives trying to kill this giant lion, for its skin was so tough that no arrow or spear could pierce it.

   Unaware of the enormity and power of the lion, Hercules attacks by shooting arrows at the lion. Creating no harm whatsoever, the angry lion retreats back into its cave where Hercules follows it inside. Blocking the entrance to the cave, Hercules takes a new approach to attacking the lion by hitting it in the head with a club stunning it. Using his bare hands, Hercules proceeds to kill the lion by strangling it with his bare hands.

   In order to prove his victory, Hercules is supposed to bring the pelt of the Nemean Lion back to King Eurystheus. Hercules tries to cut the pelt off the lion’s body before realizing that it is still impenetrable.  After trying a few different tactics, he finally figures out that the only thing that can cut the skin of the lion is its own claws. Eventually he is able to use the claws to skin the lion.  He presents the pelt to Eurystheus, completing his first trial. Hercules is said to have kept the pelt, wearing it as armor.

   In the telling of the myth, it’s said that Zeus, Hercules’s father lifted the lion up into the heavens and placed it among the stars as a way to honor his son’s first triumph. Another version tells how that after the death of the lion, Hera was filled with pity and perhaps guilt for having the creature be hunted down and killed and therefore sent it to live among the stars. Yet another version describes how Hera was furious over Hercules’s success and flung the lion into the stars.



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