Andromeda is among the 48 constellations that Ptolemy, the second-century Greco-Roman astronomer listed and until now is recognized among the 88 constellations in existence. Andromeda is a northern constellation located directly south of Cassiopeia between Pegasus and Perseus.
- Basic information about Andromeda
- Andromeda Mythology
- Andromeda Constellation Position
- Stars in the Andromeda constellation
Andromeda: Information about Andromeda
The Andromeda mythology is linked to the Greek myth that explains that Andromeda is an Ethiopian princess, daughter of Cassiopeia whose father chained her to a rock as a sacrifice to Cetus, a sea monster, but was rescued by her future husband, Perseus.
With its location at the north of the celestial equator, the Andromeda constellation is the most famous and visible at evenings in autumn in the Northern Hemisphere. Andromeda can be viewed only north of 40° South latitude, due to its northern declination; so it is found lying under the horizon for observers who are farther south.
The Andromeda constellation is among the most massive constellations having 722 square degrees area, which is more than 1400 times the size of the full moon, about 55% of the size of Hydra, the most massive constellation, and more than ten times the size of Crux, the smallest constellation.
Andromeda has a certain number of starts that are identified by their brighter and activities. Alpha Andromedae is the most shining star in the Andromeda Constellation. Besides, it is known as a binary star.
Gamma Andromedae is another start in the Andromeda Constellation; it is a colorful binary star that is slightly dimmer than Alpha. There is also Beta Andromedae, which is a red giant with color that is visible to the human eye.
Plus, there is the Andromeda galaxy (M31), which is the Andromeda constellation’s most visible deep-sky object. It is also referred to as the Great Galaxy of Andromeda and is nearest to the Milky Way.
Besides, Andromeda is home to several, other galaxies such as M110, M32 and distant NGC 891.
According to the Chinese astronomy, Andromeda is made up of 4 diverse constellations that are astrologically and mythologically significant. There is also a related constellation in the Hindu myth that is similar to Andromeda.
Andromeda related to the Greek tradition and a female image in Andromeda’s location and showed up earlier in Babylonian astronomy. The fertility goddess, also referred to as the Lady of heavens or Anunitum is represented by the stars that Pisces is made up of, and the mid-portion of the modern Andromeda.
Andromeda, in English, is called “the Chained Woman” or “the Chained Lady.” Andromeda is Perseus’s wife and daughter of Cepheus and Persea and Cepheis, respectively. In the Greco-Roman Andromeda mythology, Cassiopeia, Andromeda’s mother, the Queen of Ethiopia boasted that her daughter, Andromeda, was more exquisitely gorgeous than the sea nymphs, Nereids that possessed exquisite beauty.
The remark angered the nymphs and Poseidon was petitioned to penalize Cassiopeia for her arrogance. Poseidon commanded Cetus, the sea monster to launch an attack on Ethiopia.
Cephus, Andromeda’s father, was much afraid and consulted the Oracle of Ammon for the solution to the looming trouble. Cephus was told to offer his daughter as a sacrifice to Cetus in order to save his kingdom from danger. He chained his daughter, Andromeda to a rock by the sea but was rescued by a hero, Perseus.
Perseus was said to have slain the monster with his diamond sword while another version stated that the used the head of Medusa to cast the monster into stone. After saving Andromeda, Perseus married and two daughters. They both founded Mycenae and Persideae dynasty. After the demise of Andromeda, Athena set her in the sky as a constellation, as a mark of honor for her. Many neighboring constellations such as Cetus, Cassiopeia, Perseus, and Cepheus, and Cepheus are also characters in the Perseus myth as well as the Andromeda mythology.
People living in the Northern Hemisphere will undoubtedly notice Andromeda Constellation shine brightly from August to September each night at 10 pm lasting about 7 hours. And from October to November, Andromeda Constellation becomes visible on the eastern sky from 8 pm. It climbs higher as the midnight comes closer. It continues to move towards the north-western horizon. And between December and January, at 6 pm, Andromeda appears precisely overhead. And as spring approaches in February, it appears in the sky after 7 pm and disappears below the north-western horizon as the midnight approaches.
From the Southern Hemisphere, Andromeda appears clearly in the northern night sky. From October and November, the Constellation becomes visible around 10 pm, low close to the north-eastern horizon and shifts toward north-western horizon still visible in the sky.
Andromeda shines low in December close to the northern horizon by 10 pm and disappears below the northwestern horizons by 1 am.
Alpharatz (Alpha Andromedae)
This is the most shining star in Andromeda. It is also called “Sirrah.” Its distance from the earth is 917 light years. It is a binary star having a magnitude of +2.06. Alpharatz is both hot and blue and categorized as a BB subgiant. It is the brightest mercury-manganese star ever known in history having a luminosity 200 times that of the Sun. Alpharatz links the Andromeda Constellation to Pegasus, the horse that Perseus rode to save Andromeda.
Mirach (Beta Andromedae)
This has almost the same magnitude as Alpharatz. It is a cool, bright red class M giant, nearly 200 light years. It is 1,900 times brighter that of the Sun and about four times massive.
Almach (Gamma Andromedae)
This is the most shining star in the Andromeda Constellation and also a binary star.
- Delta Andromedae
- Iota Andromedae
- Upsilon Andromedae: This is another binary star in the Andromeda Constellation.
Andromeda Constellation and the Deep Sky Objects
Lying away from the galactic plane, Andromeda constellation does not contain any open clusters or bright nebulae of the Milky Way. However, Andromeda’s borders comprise several other visible galaxies, due to its distance from the band of obscuring gas, dust, and more stars of the galaxy.
Due to its location, Andromeda houses several “Deep Sky Objects.” Deep Sky Objects are objects in the sky that are not a star or in the solar system. They are not seen easily save through a large telescope because they are diffuse and faint. The Deep Sky Objects are categorized into:
- Open star clusters
- Global star clusters
- Diffuse Nebulae
- Dark Nebulae
- Planetary Nebulae
- Supernova Remnants
- Galaxy Groups
- Gravitational Lenses
The most popular of these Deep Sky Objects is the Andromeda Galaxy. Its distance from earth is estimated at 2.2 million light years. It is the most massive neighboring galaxy to the Milky Way and the most massive member of the Local Group of galaxies.
The Andromeda Galaxy has a total of 15 satellite galaxies with nine of them lying in a plane and two open star clusters. The Milky Way and Andromeda are spiral galaxies. The Milky Way is the galaxy that contains our solar system. The Milky Way is expanding and expected to grow into its neighbor. It is expected that Andromeda Galaxy will collide with the Milky Way in about 4 billion years.
What effects will the collision of Andromeda Galaxy with the Milky Way have on Earth and all living creatures living on the earth? Will it be a synergy?