Andromeda Galaxy

The Andromeda Galaxy, also known as the Andromeda Nebula or the Great Andromeda Nebula, is the closest spiral galaxy to the Milky Way, about 2.5 million light-years away. It is located in the eponymous constellation Andromeda and is the most distant object that can be observed with the naked eye under good conditions without technical aids. It is often referred to as M 31 for short, after its entry in the Messier catalogue.

The Andromeda Galaxy is similar to the Milky Way. Both galaxies host the same types of astronomical objects, but from the "outer" perspective of the Milky Way there is a better view of the structure of the galaxy. Dark dust bands, star forming regions, and in the outer region over 200, possibly 500 globular clusters can be made out. Also, in larger and larger areas their individual stars can be observed. The galaxy has a massive black hole of about 100 million solar masses at its center, spiral arms extend from it to a distance of about 80,000 light-years, and its halo extends over a million light-years.

In terms of halo, the Andromeda Galaxy is the largest member of the Local Group, a collection of gravitationally bound galaxies. The Andromeda Galaxy and the similarly massive Milky Way are by far the two most massive galaxies in the Local Group, and each binds a large number of satellite galaxies to itself. Estimates of the mass of the Andromeda Galaxy given in recent literature range from 0.7 to 2.5 trillion solar masses, of which its stars account for about 100 billion solar masses.

The Andromeda Galaxy has been studied scientifically for a long time. However, it was not until the end of the 19th century that this object, which previously only appeared as a nebula in telescopes, was identified as a spiral nebula formed by stars. Then, in the 1920s, the Andromeda Galaxy was used to establish that spiral nebulae are independent star systems located outside the Milky Way. This was accompanied by the realization that the universe consists of numerous other galaxies in addition to the Milky Way. Since about 1940, deviations between calculated and observed rotation in the Andromeda Galaxy have pointed to dark matter or a deviation from Newtonian dynamics. Since the turn of the millennium, more and more traces of a past collision with another galaxy have been found.

Reception

Popular Science

From the end of the 18th century, in addition to translations of Herschel's writings, popular science books on astronomy discussed the Andromeda Nebula and described its appearance; newspapers also refer to it, sometimes with sketches. In Meyers großer Conversations-Lexicon für die gebildeten Stände, published in 1841, it is described as a "well-known nebula spot" in the constellation Andromeda.

In 1885, the illustrated magazine Die Gartenlaube ran the headline "Ein Weltereigniß" ("A World Event") about the star-like illumination in the Andromeda Nebula observed at that time. Daily newspapers such as the Allgemeine Zeitung also began to report more frequently on such research results, sometimes extensively, for example on spectroscopy and attempted parallax measurements; Otto Eduard Vincenz Ule had previously given such an overview in the successful and pioneering Die Natur, "Zeitschrift zur Verbreitung naturwissenschaftlicher Kenntnisse und Naturanschauungen für Leser aller Stände", which he edited. A comprehensive overview was also given in the 1906 edition of Meyers Großes Konversations-Lexikon, together with a half-page photograph. Some articles were written by scientists, such as Julius Scheiner in the monthly Himmel und Erde published by the Urania Society, or the controversial article on the Andromeda Nebula in the 1908 supplement to the Allgemeine Zeitung or in the 1914 illustrated journal Natur.

A popular science book published in the same year 1914 by Kosmos-Verlag went one step further and summarized that the Andromeda Nebula "with a probability almost bordering on certainty" was a "distant star system [and] of all of them the one most similar to our Milky Way in construction, stage of development and form". The magazine Aus Natur und Museum added in 1922 the distance of "more than one million light years", similarly also Unsere Welt in the years 1930, 1937 and, with an explanation to the supernova 1885, in 1938. The Brockhaus Handbuch des Wissens in 4 volumes described the Andromeda Nebula in 1923 as a spectroscopically determined stellar nebula spot or spiral nebula, "far outside of our narrower star system" in a distance of more than 300.Five years later, Meyer's encyclopaedia specified a distance of one million light-years with reference to investigations by Heber D. Curtis and Edwin Hubble of the novae and Cepheids, and that "in these [spiral] nebulae one sees independent Milky Way systems located outside the Milky Way".

In an article about the Andromeda Nebula in the Kosmos series from 1938 a total mass of 100 billion solar masses as well as components corresponding to the Milky Way like open star clusters, globular clusters, although apparently somewhat darker, star forming regions and especially Cepheids are mentioned and shown in an image of the Andromeda Galaxy; in another one in 1951 the mass determination from the rotation curve and the star populations distinguished by Walter Baade are presented. The weekly newspaper Die Zeit reports in 1953 about Baade's discovery of different Cepheids and the resulting correction of the distance of the Andromeda Galaxy.

Popular science magazines devoted to the universe, such as Sirius, published from 1868, Das Weltall, published from 1900, Die Sterne, published from 1921, or Sterne und Weltraum, published from 1962, occasionally reported on special topics, mostly current research results, and paired these with selected data on the Andromeda Galaxy. Since the advent of web publications in the 1990s, popular science information about the Andromeda Galaxy has also been published in this way, sometimes by research institutions themselves. Selected results are also briefly presented in the leading media Der Spiegel, Frankfurter Allgemeine Zeitung, Süddeutsche Zeitung, Die Zeit or Neue Zürcher Zeitung as well as in Der Standard.

In addition, lectures outside of academic astronomy take place for interested audiences in various forms, sometimes on television programs, via YouTube, or as podcasts. Also in two versions of a volume of the children's and young people's non-fiction series What is what, its nature as a galaxy like the Milky Way made up of billions of stars is conveyed, supplemented by illustrations and the determination of distance by Edwin Hubble together with the current value of "around 3" and "2.5 million light years" respectively.

Image motif

The Andromeda Galaxy is offered as a picture motif on a number of everyday objects, such as pendants, mugs, T-shirts or puzzles; instructions for painting the Andromeda Galaxy with oil pastels, with acrylic paint or as a watercolour are available on YouTube. Stamps with the Andromeda Galaxy as a motif have been issued by various countries, such as the German Democratic Republic in 1967, Barbados in 1988, Mali in 1996, by Germany as a special stamp in 1999 with indentation magnetic field, by Indonesia in 2003, Bolivia in 2014, as well as by Bangladesh, Bulgaria, Estonia, France, Northern Cyprus and by Turkey for the International Year of Astronomy 2009.

Science Fiction

The prominence of the Andromeda Galaxy and its properties is reflected by its use in various genres of science fiction. Since the early 20th century, it has been addressed in a number of works in various forms. Examples of more common novels from different decades and cultural areas include:

• The Perry Rhodan series shifts plot levels to the Andromeda galaxy. For the first time at the beginning of the 100-issue cycle Master of the Island, published in 1965-1967, the protagonist Perry Rhodan and the spaceship he commands first reach the vicinity of the Andromeda Galaxy, which is inaccessible with spaceship drives, by means of a "transmitter" and then, in the further course, penetrate the galaxy itself.
• The novel The Girl from Space by the Russian author Ivan Yefremov from 1958 as well as its film adaptation locate the origin of an incidentally found stranded unknown spaceship on a planet, which is to be investigated in the future, at the end of the novel in the Andromeda Nebula, to which there was previously no connection due to the distance.
• In the novel Mutants on Andromeda by Klaus Frühauf, an earthly expedition travels to the Andromeda galaxy and has adventures there. The novel became known through a preprint in 1974 in the then high-circulation Berliner Zeitung.
• In the novel Nebel der Andromeda - Das merkwürdige Vermächtnis eines Irdischen by Fritz Brehmer, published in 1920, the protagonist teleports to an Earth-like planet of the Andromeda Nebula with an advanced civilization, where he then finds his love. The novel also picks up on the discovery of the Andromeda Nebula by Simon Marius and the distance estimation by Julius Scheiner.

Better known representatives of other genera are:

• In the comic book series Superman, which began in 1938, Superman's birth planet is located in the Andromeda Galaxy in the miniseries Superman: Birthright, published in 2004 - in contrast to the earlier depiction.
• A force attacking Earth in the anime Uchū Senkan Yamato 2 originates from the Andromeda Galaxy.
• In the episode Stone and Dust of the television series Star Trek, the Enterprise is captured by aliens from the Andromeda Galaxy who want to return there. Even using the starship's fictional propulsion technology, it would take 300 years to reach them from the Milky Way.
• In the television series Andromeda, the Andromeda Galaxy is one of the settings.
• In the German puppet show Hallo Spencer, the fairy godmother Galaktika is regularly summoned "from the distant star Andromeda".
• The 2005 film The Wild Blue Yonder is about intergalactic settlement projects between the planet of that name in the Andromeda Galaxy and Earth.
• The computer game Mass Effect: Andromeda is set in the Andromeda galaxy, which according to the backstory is reached by 4 spaceships after a journey of about 600 years from the Milky Way.

The Arbor, 1885


Indonesian stamp 1000 Rupiah "Galaksi Andromeda", 2003