Andromeda (constellation)

Coordinates: Sky map 00h 46m 00s, 37° 00′ 00″
Source: Wikipedia, the free encyclopedia.
For other uses, see Andromeda.

Andromeda
Constellation
Andromeda
List of stars in Andromeda
AbbreviationAnd[1]
GenitiveAndromedae
Pronunciation
Symbolism
19th)
Main stars16
Bayer/Flamsteed
stars		65
Stars with planets12
Stars brighter than 3.00m3
Stars within 10.00 pc (32.62 ly)3
Brightest starAlpheratz (α And) (2.07m)
Messier objects3[5]
Meteor showersAndromedids (Bielids)
Bordering
constellations
Visible at latitudes between +90° and −40°.
Best visible at 21:00 (9 p.m.) during the month of November.

Andromeda is one of the 48

88 modern constellations. Located in the northern celestial hemisphere, it is named for Andromeda, daughter of Cassiopeia, in the Greek myth, who was chained to a rock to be eaten by the sea monster Cetus. Andromeda is most prominent during autumn evenings in the Northern Hemisphere, along with several other constellations named for characters in the Perseus myth. Because of its northern declination, Andromeda is visible only north of 40° south latitude; for observers farther south, it lies below the horizon. It is one of the largest constellations, with an area of 722 square degrees. This is over 1,400 times the size of the full moon, 55% of the size of the largest constellation, Hydra, and over 10 times the size of the smallest constellation, Crux
.

Its brightest star,

Blue Snowball Nebula, a planetary nebula
, is visible in a telescope as a blue circular object.

In Chinese astronomy, the stars that make up Andromeda were members of four different constellations that had astrological and mythological significance; a constellation related to Andromeda also exists in Hindu mythology. Andromeda is the location of the radiant for the Andromedids, a weak meteor shower that occurs in November.

History and mythology

celestial atlases of the time, the constellation is a mirror image of modern maps as it was drawn from a perspective outside the celestial sphere
.
Andromeda as depicted in Urania's Mirror, a set of constellation cards published in London c. 1825, showing the constellation from the inside of the celestial sphere
Andromeda depicted in an early scientific manuscript, c.1000

The

fertility goddess, sometimes named as Anunitum or the Lady of the Heavens.[8]

Andromeda is known as "the Chained Lady" or "the Chained Woman" in English. It was known as Mulier Catenata ("chained woman") in

Cetus retreats to beyond Pisces.[11]
It is connected with the constellation Pegasus.

Andromeda was one of the original 48

Eugène Delporte as a polygon of 36 segments. Its right ascension is between 22h 57.5m and 2h 39.3m and its declination is between 53.19° and 21.68° in the equatorial coordinate system.[3]

In non-Western astronomy

Photo of the constellation Andromeda, as it appears to the naked eye. Lines have been added for clarity.

In traditional

Alpha Andromedae and Gamma Pegasi together made "Wall" (壁宿), representing the eastern wall of the imperial palace and/or the emperor's personal library. For the Chinese, the northern swath of Andromeda formed a stable for changing horses (tianjiu, 天厩, stable on sky) and the far western part, along with most of Lacerta, became Tengshe, a flying snake.[12]

An Arab constellation called "al-Hut" (the fish) was composed of several stars in Andromeda, M31, and several stars in Pisces.

ψ1 Psc were included from Pisces.[20][21]

As per Hindu astronomy, Andromeda is known as Devyani Constellation while Cassiopeia is Sharmishta Constellation. Devyani and Sharmishta are wives of King Yayati (Perseus Constellation) who is the earliest patriarch of the Kuru and Yadu Clans that are mentioned frequently in epic Mahabharat. There is an interesting story of these three characters mentioned in Mahabharat. Devyani is the daughter of Guru Shukracharya while Shar.[citation needed]

Hindu legends surrounding Andromeda are similar to the Greek myths. Ancient Sanskrit texts depict Antarmada chained to a rock, as in the Greek myth. Scholars believe that the Hindu and Greek astrological myths were closely linked; one piece of evidence cited is the similarity between the names "Antarmada" and "Andromeda".[9]

Andromeda is also associated with the

Apsu, but eventually decided to destroy them in a war that ended when Marduk killed her. He used her body to create the constellations as markers of time for humans.[9][14]

In the

Tuamotu islands, Alpha Andromedae was called Takurua-e-te-tuki-hanga-ruki, meaning "Star of the wearisome toil",[22] and Beta Andromedae was called Piringa-o-Tautu.[23]

Features

Stars

Further information: List of stars in Andromeda
Andromeda as it appears in the night sky, with the superimposed figure.
  • apparent visual magnitude of 2.1 and a luminosity of 96 L☉.[24] It is 97 light-years from Earth.[25] It represents Andromeda's head in Western mythology, however, the star's traditional Arabic names – Alpheratz and Sirrah, from the phrase surrat al-faras – [20] sometimes translated as "navel of the steed".[12][26][27] The Arabic names are a reference to the fact that α And forms an asterism known as the "Great Square of Pegasus" with 3 stars in Pegasus: α, β, and γ Peg. As such, the star was formerly considered to belong to both Andromeda and Pegasus, and was co-designated as "Delta Pegasi (δ Peg)", although this name is no longer formally used.[10][12][24]
  • b).[24] Its name comes from the Arabic phrase al-Maraqq meaning "the loins" or "the loincloth",[27] a phrase translated from Ptolemy's writing. However, β And was mostly considered by the Arabs to be a part of al-Hut, a constellation representing a larger fish than Pisces at Andromeda's feet.[20]
  • arcseconds.[11][12][26] British astronomer William Herschel said of the star: "[the] striking difference in the colour of the 2 stars, suggests the idea of a sun and its planet, to which the contrast of their unequal size contributes not a little."[30] The secondary, described by Herschel as a "fine light sky-blue, inclining to green",[30] is itself a double star, with a secondary of magnitude 6.3[11] and a period of 61 years.[24] The system is 358 light-years away.[31] Almach was named for the Arabic phrase ʿAnaq al-Ard, which means "the earth-kid", an obtuse reference to an animal that aids a lion in finding prey.[20][27]
  • orange giant of magnitude 3.3.[29] It is 105 light-years from Earth.[32]
  • type B8, 502 light-years from Earth;[33] κ And is a white-hued main-sequence star of type B9 IVn, 168 light-years from Earth;[34] λ And is a yellow-hued giant star of type G8, 86 light-years from Earth;[35] ο And is a blue-white hued giant star of type B6, 679 light-years from Earth;[36] and ψ And is a blue-white hued main-sequence star of type B7, 988 light-years from Earth.[37]
  • μ And is a white-hued main-sequence star of type A5 and magnitude 3.9.[29] It is 130 light-years away.[38]
  • planets,[40] 0.96 times, 14.57 times, 10.19 times and 1.06 the mass of Jupiter.[41] The system is 44 light-years from Earth.[42]
  • ξ And (Adhil) is a binary star 217 light-years away. The primary is an orange-hued giant star of type K0.[43]
  • π And is a blue-white hued binary star of magnitude 4.3[29] that is 598 light-years away. The primary is a main-sequence star of type B5.[44] Its companion star is of magnitude 8.9.[29]
  • 51 And (Nembus[39]) was assigned by Johann Bayer to Perseus, where he designated it "Upsilon Persei (υ Per)", but it was moved to Andromeda by the International Astronomical Union.[45] It is 177 light-years from Earth and is an orange-hued giant star of type K3.[46]
  • 54 And was a former designation for φ Per.[12][45]
  • 56 And is an optical binary star. The primary is a yellow-hued giant star of type K0 with an apparent magnitude of 5.7[29] that is 316 light-years away.[47] The secondary is an orange-hued giant star of type K0 and magnitude 5.9 that is 990 light-years from Earth.[29]
  • R And is a Mira-type variable star with a period of 409 days. Its maximum magnitude is 5.8 and its minimum magnitude is 14.8,[10] and it is at a distance of 1,250 light-years.[48] There are 6 other Mira variables in Andromeda.[24]
  • its class of variable stars. It ranges in magnitude from a minimum of 12.4 to a maximum of 8.[24] It is 2,720 light-years away.[49]
  • BY Draconis variable star of type M6.[50]
  • astronomical units from its parent star every 186 days and has a mass of 4.3 MJ.[52]
A Hertzsprung-Russel diagram for stars above 4th magnitude in the Andromeda constellation (axes not labelled).
A Hertzsprung–Russell diagram for stars brighter than 4th magnitude in the constellation Andromeda (axes not labelled).

Of the stars brighter than 4th magnitude (and those with measured luminosity), Andromeda has a relatively even distribution of evolved and main-sequence stars.

Deep-sky objects

M31, the Great Galaxy of Andromeda.

Andromeda's borders contain many visible distant galaxies.

Book of Fixed Stars.[12][56] M31 was first observed telescopically shortly after its invention, by Simon Marius in 1612.[57]

The future of the Andromeda and Milky Way galaxies may be interlinked: in about five billion years, the two could potentially begin an Andromeda–Milky Way collision that would spark extensive new star formation.[54]

Sharp view of the Andromeda Galaxy[58]

American astronomer

standard candles.[59] The distance he found was far greater than the size of the Milky Way, which led him to the conclusion that many similar objects were "island universes" on their own.[60][61][62] Hubble originally estimated that the Andromeda Galaxy was 900,000 light-years away, but Ernst Öpik's estimate in 1925 put the distance closer to 1.5 million light-years.[59]

The Andromeda Galaxy's two main companions, M32 and M110 (also known as NGC 221 and NGC 205, respectively) are faint elliptical galaxies that lie near it.[5][53] M32, visible with a far smaller size of 8.7 by 6.4 arcminutes,[11] compared to M110, appears superimposed on the larger galaxy in a telescopic view as a hazy smudge, M110 also appears slightly larger and distinct from the larger galaxy;[53] M32 is 0.5° south of the core, M110 is 1° northwest of the core.[29] M32 was discovered in 1749 by French astronomer Guillaume Le Gentil and has since been found to lie closer to Earth than the Andromeda Galaxy itself.[63] It is viewable in binoculars from a dark site owing to its high surface brightness of 10.1 and overall magnitude of 9.0.[11] M110 is classified as either a dwarf spheroidal galaxy or simply a generic elliptical galaxy. It is far fainter than M31 and M32, but larger than M32 with a surface brightness of 13.2, magnitude of 8.9, and size of 21.9 by 10.9 arcminutes.[11]

The Andromeda Galaxy has a total of 15

satellites of the Milky Way, tend to be older, gas-poor dwarf elliptical and dwarf spheroidal galaxies.[64]

The Blue Snowball Nebula as seen through the Hubble Space Telescope.

Along with the Andromeda Galaxy and its companions, the constellation also features NGC 891 (Caldwell 23), a smaller galaxy just east of Almach. It is a barred spiral galaxy seen edge-on, with a dark dust lane visible down the middle. NGC 891 is incredibly faint and small despite its magnitude of 9.9,[24] as its surface brightness of 14.6 indicates;[11] it is 13.5 by 2.8 arcminutes in size.[24] NGC 891 was discovered by the brother-and-sister team of William and Caroline Herschel in August 1783.[54] This galaxy is at an approximate distance of 30 million light-years from Earth, calculated from its redshift of 0.002.[54]

Andromeda's most celebrated

Caldwell 28) at an overall magnitude of 5.7.[24] It is a loosely scattered cluster in the Milky Way that measures 49 arcminutes across and features approximately twelve bright stars, although more than 60 stars of approximately 9th magnitude become visible at low magnifications in a telescope.[11][29] It is considered to be one of the more inconspicuous open clusters.[10] The other open cluster in Andromeda is NGC 7686, which has a similar magnitude of 5.6 and is also a part of the Milky Way. It contains approximately 20 stars in a diameter of 15 arcminutes, making it a tighter cluster than NGC 752.[24]

There is one prominent planetary nebula in Andromeda: NGC 7662 (Caldwell 22).[24] Lying approximately 3 degrees southwest of Iota Andromedae at a distance of about 4,000 light-years from Earth, the "Blue Snowball Nebula"[11] is a popular target for amateur astronomers.[65] It earned its popular name because it appears as a faint, round, blue-green object in a telescope, with an overall magnitude of 9.2.[11][65] Upon further magnification, it is visible as a slightly elliptical annular disk that gets darker towards the center, with a magnitude 13.2 central star.[11][29] The nebula has an overall magnitude of 9.2 and is 20 by 130 arcseconds in size.[24]

Meteor showers

Each November, the Andromedids meteor shower appears to radiate from Andromeda.[66] The shower peaks in mid-to-late November every year, but has a low peak rate of fewer than 2 meteors per hour.[67] Astronomers have often associated the Andromedids with Biela's Comet, which was destroyed in the 19th century, but that connection is disputed.[68] Andromedid meteors are known for being very slow and the shower itself is considered to be diffuse, as meteors can be seen coming from nearby constellations as well as from Andromeda itself.[69] Andromedid meteors sometimes appear as red fireballs.[70][71] The Andromedids were associated with the most spectacular meteor showers of the 19th century; the storms of 1872 and 1885 were estimated to have a peak rate of 2 meteors per second (a zenithal hourly rate of 10,000), prompting a Chinese astronomer to compare the meteors to falling rain.[68][72] The Andromedids had another outburst on December 3–5, 2011, the most active shower since 1885, with a maximum zenithal hourly rate of 50 meteors per hour. The 2011 outburst was linked to ejecta from Comet Biela, which passed close to the Sun in 1649. None of the meteoroids observed were associated with material from the comet's 1846 disintegration. The observers of the 2011 outburst predicted outbursts in 2018, 2023, and 2036.[73]

See also

  • Andromeda (Chinese astronomy)
  • Qatar-3

References

Citations

  1. ^ Russell 1922, p. 469.
  2. ^ a b c Allen 1899, pp. 32–33.
  3. ^ a b c IAU, The Constellations, Andromeda.
  4. ^ Ridpath, Constellations.
  5. ^ a b Bakich 1995, p. 54.
  6. ^ Bakich 1995, p. 26.
  7. ^ a b RECONS, The 100 Nearest Star Systems.
  8. ^ Rogers, Mediterranean Traditions 1998.
  9. ^ a b c d Olcott 2004, pp. 22–23.
  10. ^ a b c d e f g h i Moore & Tirion 1997, pp. 116–117.
  11. ^ a b c d e f g h i j k l m n Thompson & Thompson 2007, pp. 66–73.
  12. ^ a b c d e f g h i j Ridpath, Star Tales Andromeda.
  13. ^ Pasachoff 2000, p. 132.
  14. ^ a b c Staal 1988, pp. 7–14, 17.
  15. ^ "The Andromeda Galaxy and the Double Cluster in al-Sufi's Book of the Fixed Stars". Ian Ridpath's Star Tales. Retrieved 21 November 2022.
  16. ^ a b Bakich 1995, p. 43.
  17. ^ Bakich 1995, p. 11.
  18. ^ Pasachoff 2000, pp. 128–129.
  19. ^ Russell 1922, pp. 469–471.
  20. ^ a b c d Davis 1944.
  21. ^ "The Great Fish (al-hut): The 28th Arab lunar station". Two Deserts, One Sky. Retrieved 21 March 2024.
  22. ^ Makemson 1941, p. 255.
  23. ^ Makemson 1941, p. 279.
  24. ^ a b c d e f g h i j k l m Moore 2000, pp. 328–330.
  25. ^ SIMBAD Alpha And.
  26. ^ a b Ridpath & Tirion 2009, pp. 61–62.
  27. ^ a b c Odeh & Kunitzsch 1998.
  28. ^ a b SIMBAD Mirach.
  29. ^ a b c d e f g h i j k Ridpath 2001, pp. 72–74.
  30. ^ a b French 2006.
  31. ^ SIMBAD Gamma1 Andromedae.
  32. ^ SIMBAD Delta Andromedae.
  33. ^ SIMBAD Iota And.
  34. ^ SIMBAD Kappa Andromedae.
  35. ^ SIMBAD Lambda Andromedae.
  36. ^ SIMBAD Omicron Andromedae.
  37. ^ SIMBAD Psi Andromedae.
  38. ^ SIMBAD 37 Andromedae.
  39. ^ a b c "Naming Stars". IAU.org. Retrieved 30 July 2018.
  40. S2CID 10934982
    .
  41. ^ ExoPlanet ups And.
  42. ^ SIMBAD Ups And.
  43. ^ SIMBAD Xi Andromedae.
  44. ^ SIMBAD 29 And.
  45. ^ a b Wagman 2003, p. 240.
  46. ^ SIMBAD 51 And.
  47. ^ SIMBAD 56 And.
  48. ^ SIMBAD R And.
  49. ^ SIMBAD Z And.
  50. ^ SIMBAD HH And.
  51. ^ SIMBAD 14 And.
  52. ^ ExoPlanet Planet 14 And b.
  53. ^ a b c d Pasachoff 2000, p. 244.
  54. ^ a b c d e f g Wilkins & Dunn 2006, pp. 348, 366.
  55. ^ Bakich 1995, p. 51.
  56. ^ a b Higgins 2002.
  57. ^ Rao 2011.
  58. ^ "Sharpest ever view of the Andromeda Galaxy". www.spacetelescope.org. ESA/Hubble. Retrieved 14 January 2015.
  59. ^ a b Hoskin & Dewhirst 1999, pp. 292–296.
  60. ^ ESA, Edwin Powell Hubble.
  61. ^ PBS, Edwin Hubble 1998.
  62. ^ HubbleSite, About Edwin Hubble 2008.
  63. ^ Block 2003.
  64. ^ Koch & Grebel 2006.
  65. ^ a b Pasachoff 2000, p. 270.
  66. ^ Bakich 1995, p. 60.
  67. ^ Lunsford, Meteor Shower List 2012.
  68. ^ a b Jenniskens 2008.
  69. ^ Lunsford, Activity Nov 19–23 2011.
  70. ^ Sherrod & Koed 2003, p. 58.
  71. ^ Jenniskens & Vaubaillon 2007.
  72. ^ Jenniskens 2006, p. 384.
  73. ^ Wiegert et al. 2012.

Bibliography

Online sources

SIMBAD

  • "Alpha And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 April 2012.
  • "Mirach". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 April 2012.
  • "Gamma1 Andromedae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2012.
  • "Delta Andromedae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 April 2012.
  • "Iota And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2012.
  • "Kappa Andromedae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2012.
  • "Lambda Andromedae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2012.
  • "Omicron Andromedae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2012.
  • "Psi Andromedae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2012.
  • "37 Andromedae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 April 2012.
  • "Ups And – High proper-motion Star". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 April 2012.
  • "Xi Andromedae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 April 2012.
  • "29 And (Pi And)". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 April 2012.
  • "51 And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2012.
  • "56 And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 April 2012.
  • "R And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2012.
  • "Z And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 1 May 2012.
  • "HH And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 20 May 2012.
  • "14 And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 20 May 2012.

External links

Media related to Andromeda (category) at Wikimedia Commons

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