Cancer is one of the twelve constellations of the zodiac, located in the northern hemisphere, ranking 31st among the constellations with the largest celestial space, covering an area of 506 square degrees. It can be seen at latitudes between +90° and -60°. In the constellation Cancer It is well known but many people do not know how to find it in the sky.
In this article we are going to tell you all the characteristics, origin and meaning of the Cancer constellation.
Key features
Cancer has the peculiarity that it is the most tenuous of the signs of the zodiac. It has no stars of magnitude less than 3. It's not particularly large, but it ranks 31st from largest to smallest among the 88 modern constellations. It covers a total area of 506 square degrees.
The constellation is located in the second quadrant of the northern hemisphere and is visible from any latitude above 60 degrees south. Its neighboring constellations are Lynx, Gemini, Canis Minor, Hydra, Leo, and Leo Minor. In the zodiac, it lies between Leo and Gemini. This constellation contains different galaxies and Messier objects of great interest to astronomers.
Origin and mythology of the constellation Cancer
In Greek mythology, crabs are associated with the twelve labors of the hero Hercules. According to mythology, the crab was sent by Hercules' enemy, the goddess Hera, to distract him when he faced the monster Hydra. Hercules was able to defeat the Hydra and the Crab and place the two creatures in the sky as constellations.
In ancient times, the summer solstice occurred in the constellation Cancer. Currently, the summer solstice has moved into Taurus due to the precession of the vernal equinoxes.
Stars of the constellation Cancer
Cancer is a dim sign. It has no stars below magnitude 3, and only two stars below magnitude 4. Although less luminous, the constellation has 104 stars below magnitude 6,5, so it can be seen with the naked eye if weather conditions are mild. good.
The following stars are some of the most important in the constellation.
- Alpha Cancri: is a star system consisting of at least two stars (possibly three). The main component is a white dwarf star of magnitude 4,26. This makes the star the fourth brightest star in the constellation. The star is also known as Acubens, which means crab claw in Arabic. Another name used to designate this star is Sertan.
- Beta Cancri: It is also known as Altarf, which means sharp point in Arabic. This is the brightest star in the constellation Cancer with an apparent magnitude of 3,5. The star is an orange giant located 290 light years from our solar system. One of the peculiarities of this star is that it has a massive planet orbiting it. The planet is estimated to be eight times more massive than Jupiter.
- Delta Cancri: is an optical binary star formed by Delta Cancri A and Delta Cancri B. Delta Cancri A is another double star, also known as Asellus Australis, which means southern donkey in Latin. It is located 180 light years from the Solar System and has an apparent magnitude of 3,94. It is very close to the ecliptic and is sometimes obscured by the Moon.
- Gamma Cancri: It is also a stellar system 158 light years from the Solar System with an apparent magnitude of 4,66. Its traditional name is Asellus Borealis, which means northern donkey. It lies close to the ecliptic along with Alpha Cancer and Delta Cancer and is sometimes hidden by the Moon and even some planets.
- Iota Cancri: is a binary star located 300 light years from our solar system. The primary component is a yellow giant star, and the secondary component is a white dwarf. The two stars have apparent magnitudes of 4,03 and 6,58, respectively. This makes its first component the third brightest star in the constellation.
- Zeta Cancri: also known as Tegmine, it is actually a multi-star system with at least five stars. The system is about 83,4 light years from the Solar System. The first component, called Zeta 1 Cancri, is a binary star made up of Zeta Cancri A and Zeta Cancri B. Zeta Cancri A is the brightest star in the group, with an apparent magnitude of 5,63. The second component is a triple star called Zeta 2 Cancri. This star system consists of Zeta Cancri Ca and the binary star Zeta Cancri Cb.
other stars
The rest of the stars in Cancer are all larger than the fifth magnitude. Among them, It is worth mentioning two stars with planetary systems made up of 5 planets.
From a scientific point of view, the most interesting star is 55 Cancri. This is a binary star 41 light years from our solar system, and its planetary system contains at least 5 planets. Of the five planets, four are gas giants and one is a carbon planet. The five planets are named Jansen, Galileo, Brahe, Harriot, and Libercy.
There is also a planetary system of five planets around the star HIP 41378. In this case, the planets are estimated to be between the mass of Earth and twice the mass of Jupiter.
Curiosities of the constellation of Cancer
- It can be seen in both the northern and southern hemispheres.
- The ecliptic crosses the center of the constellation between the end of July and the beginning of August.
- Cancer is located 30º north of the Milky Way and, as such, it is characterized by two beautiful star clusters and many double stars.
- In the northern hemisphere it can be seen from late autumn to spring, while in the southern hemisphere it can be seen in summer and fall and appears in the middle of the night.
- It has no first-magnitude stars, the stars are very faint, and the constellation's brightest star is Altarf, which is 500 times brighter than the sun.
- The shape of Cancer in the sky is not like a crab, but an inverted "Y".
- It is visible in the northern hemisphere, especially in early spring, and in the southern hemisphere in early fall.
- The meaning of Cancer in Latin is crab.
- The Tropic of Cancer is named after this constellation, a line of latitude that marks the northernmost point at which the sun can be seen directly overhead.
- It is based on a 3000 year old Babylonian constellation known as the Crab.
- Has Tau Cancrids meteor shower
- There are 104 stars in this constellation, of which 50 are visible to the naked eye.
I hope that with this information you can learn more about the constellation of Cancer and its characteristics.