The Ursa Minor Constellation

Ursa Minor - The Little Bear

Did you know we have a little bear in the sky?

Yep, you heard it right!

Ursa Minor Constellation, housing the most renowned star “Polaris”, is also known as the little bear as per Roman Mythology. It is also called “The Little Dipper”, due to its shape and design. Read on to find out all the facts and myths related to Ursa Minor.

Ursa Minor constellation lights up the Northern sky. Due to Polaris's presence, the Ursa Minor constellation has been used as a navigation tool by mariners since the early ages.

Second Century Astronomer, Ptolemy listed it as one of the 48 constellations and it remains among the 88 constellations. However, it is believed that Thales of Miletus, a philosopher, and astronomer belonging to the 625 to 545 BC era, was the one who actually created the Ursa Minor. Thales is also known to be one of Greece's seven sages, philosophers of the early 6th century known for their wisdom. Thales was believed to be a descendant of the Phoenician family who often used Ursa Minor for navigation purposes. It offered better guidance being so close to the North Pole. Hence the name "Phoenician bear" for the constellation came to be.

Ursa Minor Characteristics

Location – Ursa Minor

Ursa Minor is surrounded by the constellations Camelopardalis, Draco and Cepheus. It is 56th constellation based upon its size and covers an area of 256 square degrees. Since Ursa Minor is located in the Northern hemisphere or NQ3, it can be seen at latitudes +90 degrees and -10 degrees. It resides under Ursa Major constellation family, including Bootes, Camelopardalis, Coma Berenices, Canes Venatici, Draco, Lynx, Corona Borealis, Leo Minor, and Ursa Major.

By Till Credner - Own work: AlltheSky.com

Shape – Ursa Minor

The Ursa Minor constellation forms a ladle, spoon, scoop, or dipper and, therefore, known as the little dipper in the U.S. The shape of a ladle is formed by seven stars, with four stars forming the bowl while another three celestial bodies make up a handle. Polaris makes the top of the handle!

Little dipper is not to be confused with the big dipper constellation, also known as the Ursa Major constellation. Although both constellations are shaped in the form of a ladle, the difference between the two can be spotted by the shape of the handle and, of course, the Polaris. The Big dipper has a concave handle. Moreover, the stars in the big dipper are of much larger magnitude as compared to the little dipper. The little dipper has a convex handle which makes it more recognizable. Both the dippers have a similar kind of asterisms. However, the Ursa Minor Constellation has only three stars visible; meanwhile, Ursa Major has more visible stars, making it easier to locate.

Polaris – the Brightest Star in the Ursa Minor Constellation

Polaris or Alpha Ursae Minoris is famously called the Pole star or North star because the whole northern sky moves around it. It is known for holding nearly still due to its positioning at the north celestial pole— the point of rotation for the northern sky. Polaris has a magnitude of 1.97 - 2.00. It is a yellow-white supergiant star shining bright in the northern sky.

Other Stars in Ursa Minor:

Ursa Minor has five named stars including Polaris. These are Kochab, Pherkad, Baejdu and Yil dun. Kochab and Pherkud, otherwise known as Beta Ursae Minoris and Gamma Ursae Minoris respectively, have been named the "guardians of the pole star". Kochab has cooled down and become swollen with time. It is now an orange giant of the magnitude of 2.08. While the other guardian, Pherkud has a magnitude of 3.

Some planets have been identified as orbiting the stars in the Little Dipper. An isolated neutron star called the Calavera is also located in this constellation. It is the hottest white dwarf with a surface temperature of 200,000 K.

Ursa Minor Mythology:

There are three major myths associated with Ursa Minor Constellation:

Ida, The Nymph

In the first myth, the constellation symbolizes the nymph Ida who used to take care of Zeus. Zeus's mother, the Rhea, hid him from his father on the island of Crete when he was a little child along with Ida and Adrastea, another nymph who is represented by the Ursa Major.

Cronos, Zeus's father, feared an old prophecy that one day one of his own offspring will overthrow his throne and will become the supreme god. In his fear of losing his throne, he swallowed all five of his children.

Rhea could not bear to lose another child, so when she hid newly born Zeus on the island while making Cronos swallow a stone to trick him into believing that Zeus is gone. Therefore, the prophecy was fulfilled when Zeus grew up. He took over the throne, rescued his siblings, and became the supreme god of Olympus.

Arcas - The Little Bear

The second myth is related to the constellation being called the little bear. According to this myth, constellation represents Arcas and Callisto. Arcas was the son of Zeus, and Callisto was a nymph. Callisto who had sworn her chastity to Artemis couldn't resist the advances made by Zeus and ultimately gave in. She gave birth to two children, one of whom was named Arcas.

When Hera, wife of Zeus, found out about the child, she transformed Callisto into a bear so that Zeus won't be attracted to her. However, one day Arcas had an encounter with Callisto in her bear form and was about to kill her. Fortunately, Zeus saw the whole thing in time, and a whirlwind scooped both the child and the mother. He had them turned into the constellations. Callisto became Ursa Major or the bigger bear constellation, whereas Arcas became Ursa Minor or the little bear constellation. Ursa Minor is actually Latin for "lesser bear."

The Hesperides

In another older myth, the seven stars in the Ursa Minor Constellation symbolize the Hesperides, daughters of Atlas.