Ursa Major: The Ultimate Guide
Ursa Major (Great Bear)
Ursa Major, or "Big Dipper," is one of the most famous constellations in the sky. The constellation's name comes from the Latin "Ursa Major" as its size is more significant when compared to the "Ursa Minor," which is a constellation with a shape similar to that of Ursa Major.
The constellation Ursa Major is one of the easiest to see in the sky due to its brightness and proximity to the north pole.
The fastest way to recognize it is by asterism of the main seven stars. These form what observational astronomers call "Big Dipper" because of their remarkable resemblance to that of a casserole.
The constellation Ursa Major is home to deep-sky objects such as galaxies. In addition, within the constellation's boundaries, several essential meteor showers are occurrences.
The Mythology And History Of The Ursa Major Constellation
Ancient Egypt
In ancient Egyptian culture, the go astrologers had two words to refer to Ursa Major's constellation.
The first word was "Khepesh," meaning "the thigh" or "the leg of an ox"; the second word was "Meskheti," meaning "the striker" or "the bull."
Usually, in the hieroglyphs, it was also attributed to the shape of a carriage or a plow towed by animals or people.
Greek Mythology
The ancient Greeks defined different stories for Ursa Major's constellation, usually associated with pack animals, carriages, or giant beasts. It is the third-largest constellation in the night sky.
The best-known star pattern in the entire northern hemisphere sky is the seven stars that make up the form popularly called "Big Dipper."
The Big Bear got that name because the Greeks realized two constellations whose brightest stars had a similar pattern, so they decided to call the most extensive "Big Bear" and the smaller "Little Bear."
Its Greek name in the Almagest was Ἄρκτος Μεγάλη" (Arktos Megale) which in Latin translates as "Ursa Major."
Early Modern Period
During the fourth to seventh centuries, the constellation acquired different names; among the most used was "The Great Plough," "Big Bear," or the "The Carriage," all these names came from ancient European cultures.
However, the constellation was repressed like a bear by the Jewish peoples responsible for spreading that name throughout the continent.
Later during the fourth century, the "Big Bear" name by which the constellation was known was translated as "Arcturus" in the Vulgata, a Latin translation of the Bible.
Because of this, the constellation would remain with that name officially for many centuries afterward.
In addition, during the seventeenth to ninth centuries, this constellation was used by sailors and pirates to locate the star Polaris, which marks the north pole and served them not to get lost in the ocean.
Nowadays
Ursa Major's constellation is now officially known as "Ursa Major" because astronomers agreed that the original name should be retained.
The International Astronomical Union officially recognizes the constellation with this name, and no changes have been made to its borders.
Ursa Major remains the third largest constellation of all, occupying an area of 1280 square degrees.
How To Find The Ursa Major Constellation?
Visibility By Region
Ursa Major resides in the second quadrant of the northern hemisphere (NQ2) at latitudes between 16° S and 90° N. We can see the constellation in the night sky from all countries in the northern and some countries of the southern hemisphere.
Ursa Major is not visible in several southern hemisphere countries, such as Chile, Argentina, Madagascar, South Africa, southern Australia, New Zealand, much less Antarctica.
Visibility By Season
Being a constellation very close to the north pole Ursa Major is visible throughout the year for the countries where it is possible to see it. This means it is a Circumpolar constellation.
Due to its position in the sky, the hours seen in the sky change throughout the year. During the winter, it is visible after midnight and during the summer at sunset.
The best month to see Ursa Major's constellation is April, when the sky presents less precipitation due to spring temperatures.
Finding Ursa Major Constellation
Ursa Major is near the north pole, so it will be easy to find if you know how to locate the north.
The easiest way to locate it is with the asterism of 7 stars that form the saucepan. These four stars form the handle of the dipper point it in the opposite direction to the north polar star.
Related Constellations
The bordering constellations with Ursa Major are Bootes, Camelopardalis, Canes Venatici, Draco, Leo, Leo Minor, and Lynx.
Ursa Major belongs to the family of constellations of Ursa Major, along with Boötes, Camelopardalis, Canes Venatici, Coma Berenices, Corona Borealis, Draco, Leo Minor, Lynx, and Ursa Minor.
Stars in Ursa Major Constellation
The Big Dipper officially contains 209 stars; the International Astronomical Union (IAU) designated a formal name for 22 of these stars; these are Alcor, Alioth, Alkaid, Alkaphrah, Alula Australis, Alula Borealis, Aniara, Chalawan, Dombay, Dubhe, Intercrus, Liesma, Megrez, Merak, Mizar, Muscidae, Násti, Phecda, Taiyangshou, Talitha, Tania Australis, and Tania Borealis.
Of those 22 stars, 7 form the famous prominent saucepan-shaped asterism; these seven stars are Alioth, Alkaid, Dubhe, Megrez, Merak, and Mizar.
The brightest star before the Big Dipper is Alioth "Epsilon Ursae Majoris," with a magnitude of 1.76.
ε Ursae Majoris (Alioth)
The brightest star in the constellation is Alioth, a white star of spectral type A0p 108 times more luminous than the Sun.
It is 81 light-years from Earth, is four times larger than the Sun, and its mass is three times that of the Sun.
α Ursae Majoris (Dubhe)
The second brightest star in the constellation is α Ursae Majoris Dubhe, a multiple star system consisting of Dubhe A, a yellow-orange giant star, and Dubhe B, a white-yellow main-sequence star.
γ Ursae Majoris (Phecda, Phekda or Phad)
With an apparent magnitude +1.85, Gamma Ursae Majoris is the third brightest star in the constellation.
It is located 101 light-years away and is a blue-white main-sequence star of spectral type B3V.
Other Ursa Major Stars:
- δ Ursae Majoris (Megrez)
- ζ Ursae Majoris (Mizar)
- η Ursae Majoris (Benetnasch or Alkaid)
- θ Ursae Majoris
- ι Ursae Majoris (Talitha Borealis)
- κ Ursae Majoris (Talitha Australis)
- λ Ursae Majors (Tania Borealis)
- μ Ursae Majoris (Tania Australis)
- and Ursae Majoris (Alula Borealis)
- ξ Ursae Majoris (Alula Australis)
- ο Ursae Majoris (Muscida)
- π Ursae MajorisUrsae Majoris
- ρ Ursae Majoris
- υ Ursae Majoris
- HD 89744
- Lalande 21185
- Groombridge 1830
- Groombridge 1618
- HR 5256 (HD 122064)
- G 196-3
- Sidus Ludoviciana
- φ Ursae Majoris
- χ Ursae Majoris (Al Kaphrah)
- ψ Ursae Majoris
- W Ursae Majoris
- AW Ursae Majoris
- IQ Ursae Majoris (83 Ursae Majoris)
- 15 Leonis Minoris
- 16 Ursae Majoris (c Ursae Majoris)
- 23 Ursae Majoris
- 24 Ursae Majoris (DK Ursae Majoris)
- 47 Ursae Majoris
- 36 Ursae Majoris
- 61 Ursae Majoris
- 55 Ursae Majoris
- 78 Ursae Majoris
- 80 Ursae Majoris (Alcor)
- HD 98618
- Gliese 412 (WX Ursae Majoris)
- Gliese 450
- HIP 57050
Deep Sky Objects
Ursa Major is also known as the home of several deep-sky objects. Deep-sky objects often mean star clusters, nebulae (interstellar cloud bodies), or galaxies. In the case of Ursa Major, it is rich in several notable galaxies.
M81 or Bode's Galaxy
A spiral galaxy located 12 million light-years away in the constellation Dipper contains approximately 250 billion stars. It is slightly smaller than the Milky Way.
M82 (Cigar Galaxy)
M82 is an elongated and narrow irregular galaxy; it is characterized by being the prototype of a galaxy with a stellar outbreak; that is, within it, a large number of stars are born recurrently.
Like M81, it is located 12 million light-years from our galaxy.
M97 or Owl Nebula
The Owl Nebula is named after Lord Rosse, who associated its shape with that of the animal; it is a planetary nebula located 2600 light-years from the solar system.
Other Deep-sky Objects Of Ursa Major:
- Pinwheel Galaxy (M101)
- M101 Group.
- Spiral galaxy M108
- Spiral galaxy M109
- NGC 3949
- NGC 3953
- NGC 3982
- NGC 4088
- NGC 2841
- NGC 3079
- NGC 3184
- NGC 3310
- NGC 4051
- NGC 4013
- NGC 3077, elliptical galaxy
- NGC 2685, lenticular galaxy
- Zwicky 18, irregular galaxy
- Hubble Deep Field
Meteor Showers
In the region comprising the constellation Ursa Major, a shower of stars called "Ursid" extends from December 17 to 26 of each year.
The peak of exposure of the Ursids is the morning of December 22, although depending on the phase in which the moon is, this date can move a few days.
In 2021 the date of most excellent exposure will be December 21 due to the presence of the full moon.
Interesting Facts
- In Greek mythology, the constellation of the Big Dipper sometimes was considered to be the bear into which Artemis had converted Callisto on the orders of Zeus.
- Ursa Major is one of the few constellations mentioned in the Bible, along with Orion and the Pleiades.
- The constellation Ursa Major appears on the flag of Alaska. It was of great historical importance for navigation because it was used to locate the polar star pointing north.
Conclusions
- Ursa Major is the third largest constellation in the night sky. It has been vital in the historical context due to its proximity to the north pole.
- Ursa Major comes from the Latin "Ursa Major," derived from Greek mythology. This constellation was associated with a Bear's offspring, the "Ursa Minor."
- It is also commonly known as the Big Dipper due to its casserole shape.
- Ursa Major is a northern constellation that is visible all year round. Also, it is possible to see it from some countries in the southern hemisphere, such as Brazil, Peru, Venezuela, Kenya, or Indonesia.
- Ursa Major is one of the easiest constellations to locate due to its asterism of 7 casserole-shaped stars.
- The brightest star in the Big Dipper is Alioth "Epsilon Ursae Majoris," with a magnitude of 1.76.
- The most notable galaxy within the borders of Ursa Major is M81 or Bode Galaxy, which is a prominent spiral galaxy slightly smaller than the Milky Way.
- The strongest meteor shower in Ursa Major is the "Ursid."