The constellation of Ursa Major is the largest constellation located in the northern hemisphere and the third biggest constellation that can be seen in the night sky.
Key Facts & Summary
- Ursa Major is an ancient constellation and one of the 48 constellations discovered by Ptolemy in the second century A.D.
- The constellation of Ursa Major is often associated with the legend of Callisto, a greek nymph.
- Ursa Major is the third largest constellation in the sky, covering up to 3.10% of the entire sky.
- Its brightest star is Alioth, with a magnitude of 1,77, and it is the 31st most luminous star in the night sky.
- Ursa Major is visible throughout the year in the northern hemisphere.
- Seven of its stars form the Big Dipper asterism, an essential tool used in navigation.
- The stars Dubhe and Merak are used to find the North Star, as they point to its direction.
- Two meteor showers occur every year, and they appear from the direction of Ursa Major.
- These meteor showers are known as the Ursa Majorids and the Leonids-Ursids.
- The constellation of Ursa Major never sets below the horizon.
- The brightest stars in Ursa Major, and the ones which form the star pattern known as the Big Dipper, are Dubhe, Merak, Phecda, Megrez, Alioth, Mizar, and Alkaid.
- The constellation of Ursa Major is depicted on the flag of Alaska.
- There are seven Messier objects in this constellation, namely the binary star Messier 40, many galaxies such as Messier 81, 82, 101, 108, 109, and the famous nebula known as Messier 97.
- There are 21 stars located in the constellation of Ursa Major, which host planets. There may be even more!
- The Big Dipper asterism is called the North Dipper in Asian countries such as China and Japan.
The Constellation of Ursa Major for Kids
The constellation of Ursa Major is an ancient constellation that depicts a giant bear. Its name translates to the "greater bear" – the little bear being Ursa Minor, which is close to it.
Bears were venerated by our ancients as being the strongest animal to roam the land. The constellation of Ursa Major hosts one of the most famous asterisms, namely The Big Dipper, or also known as The Plough.
What is the Constellation of Ursa Major?
The constellation of Ursa Major is one of the oldest known constellations in the sky. Its first official mention was in the second century, and it was part of the 48 original constellations listed by Claudius Ptolemy, a Greek astronomer and mathematician.
Nowadays there are 88 modern constellations recognized by the International Astronomical Union (IAU). However, the constellation of Ursa Major can be traced even earlier in time. Both Homer, a Greek author from the VIII century B.C., and the Bible, references this constellation in their writings.
What is the Story behind the Constellation of Ursa Major?
There are many legends and stories regarding Ursa Major, and in most of them, the constellation is associated with a bear. Even its name, Ursa Major, is Latin for The Great Bear.
According to Greek mythology, Zeus, the king of gods, fell in love with Calisto, a nymph who had sworn a chastity vow to Artemis. Even though their love was forbidden, a child was born under the name of Arcas. Soon after, Hera, Zeus' wife, found out about her husband's infidelity, and out of jealousy, she turns the beautiful Callisto into a bear, hoping that Zeus will no longer love her.
Callisto spends the next 15 years wandering through the woods and hiding from hunters. But one day, she encounters her son, Arcas, and as he doesn't recognize her, he draws his spear and attempts to hurt her.
When Zeus sees what is about to happen, he sends a whirlwind to avert the upcoming tragedy. He carries both Callisto and Arcas into the sky. There, he turns his son into the constellation of Ursa Minor and his lover, Callisto, into Ursa Major.
Why is Ursa Major Important?
The constellation of Ursa Major completes a full rotation around the North Star every 24 hours, and for that reason, it can never be seen below the horizon.
Because of this motion, the constellation has been used as a star clock throughout history. Just from looking at its position in relation to the North Star, people could tell the clock during night time.
Fun Kids Facts About Ursa Major
- In South Korean mythology, Ursa Major is also called "The seven stars of the north." It is said that a widow, along with her seven sons, used to go by the house of a widower, but in order to get there, they had to cross a river. Each son places a stone into the water so that it would be easier to get to the other side. The mother didn't know who put the stepping stones there, so she blessed them, and when her sons died, they became the constellation of Ursa Major.
- There are two meteor showers within the constellation of Ursa Major: the Alpha Ursa Majorids and the Leonids-Ursids.
- The Ursa Major was mentioned in important writings throughout time, some of the most memorable being the works of Homer, Spenser, Shakespeare, and Tennyson.
- Vincent van Gogh illustrated the constellation of Ursa Major in one of his paintings, "Starry Night Over the Rhône."
Size and Comparison
Ursa Major is the largest constellation located in the northern hemisphere and the third largest constellation in the sky. It covers 1279.66 square degrees, which means 3.10% of the full sky.
Ursa Minor vs Ursa Major
Ursa Minor, the Little Bear, and Ursa Major, the Great Bear, are two distinct constellations located in the northern hemisphere. They both shared the same legend throughout history and also the same importance in navigation.
What Are the Main Stars of Ursa Major?
The constellation of Ursa Major is made up of 22 stars. Ursae Majoris, also known as Alioth, is the brightest star of this constellation and the 33rd brightest in the sky. Along with six other stars, Dubhe, Merak, Phecda, Megrez, Mizar, and Alkaid, it forms the Big Dipper asterism.
Mizar, the second star from the end of Big Dipper's handle and the third brightest star of this constellation, is known for its spectacular optical illusion.
Together with Alcor, it forms a famous double star that in the Arab culture is referred to as "the horse and the rider." It can be easily seen with the bare eye if the sky is clear.
What is the Big Dipper?
The Big Dipper is an asterism, one of the most recognizable in the night sky, and it is part of the constellation of Ursa Major. It consists of seven bright stars, with magnitudes that go from 1.8 to 2.4.
What is the Big Dipper Used For?
The Big Dipper is mainly used as a navigation tool because it serves as a pointer to other locations in the sky. For example, if you draw a straight line up, continuing the imaginary line between Merak and Dubhe, you will reach the North Star, also known as Polaris.
Similarly, if you continue the Dipper's handle, you will find the bright star Arcturus, and if you keep going, you will discover Spica, one of the brightest stars in the sky and the most shining star in the constellation of Virgo.
What Does the Little Dipper Do?
The North Star can also be used to find your latitude on Earth: if you are near the equator, Polaris will be near the horizon, but if you are at the North Pole, the star will be right above you.
Other Characteristics of Ursa Major
The constellation of Ursa Major is placed in the second quadrant of the northern hemisphere, and it is visible for most of the year everywhere around the Globe.
Ursa Major lies between +90 ° and - 30 ° latitude, and it has been a point of reference to many cultures throughout history.
Ursa Major Notes
- Ursa Major is the third largest constellation in the sky.
- Seven of its stars form the Big Dipper asterism. They are Dubhe, Merak, Phecda, Megrez, Alioth, Mizar, and Alkaid.
- It is visible throughout the year in most of the northern hemisphere.
- Ursa Major never sets below the horizon.
- The brightest star in the constellation of Ursa Major is Alioth.
- The stars Dubhe and Merak are used to find the North Star – Polaris - as they point in its direction.
- These meteor showers are known as the Ursa Majorids and the Leonids-Ursids.
- There are 21 stars located in the constellation of Ursa Major, which hosts planets.