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Orion's Belt

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This article is about the group within the constellation Orion. For other uses, see Orion's Belt (disambiguation).

Orion's Belt
Orion's Belt and nebulosity, including the Flame Nebula (left) and Horsehead Nebula (lower left) named after a relatively small dark cloud, rotated 90° somewhat resembling a seahorse
Observation data
Right ascension05h 00m 00s[1]
Declination−05° 00′ 00″[1]
Physical characteristics
Associations
ConstellationOrion
See also: Open cluster, List of open clusters

Orion's Belt is an asterism in the constellation of Orion. Other names include the Belt of Orion, the Three Kings, and the Three Sisters.[1] The belt consists of three bright and easily identifiable collinear star systems – Alnitak, Alnilam, and Mintaka – nearly equally spaced in a line, spanning an angular size of ~140′ (2.3°).[2]

Owing to the high surface temperatures of their constituent stars, the intense light emitted are blue-white in color, aiding in the recognition of the familiar astronomical motif. In spite of their spot-like appearance, only Alnilam is a single star; Alnitak is a triple star system, and Mintaka a hextuple. Each of the three owe their luminosity to the presence of one or more blue supergiants. The brightest as viewed from Sol is Alnilam, with an apparent magnitude of 1.69,[3] followed by Alnitak at 1.74[4] and Mintaka at 2.25.[5] Together, the 10 stars of the three systems has a combined luminosity of nearly one million times (~970,000) that of the Sun's.

Orion's Belt has been called various names and mentioned in various cultures and literature. It has played a central role in astral navigation in the Northern hemisphere since prehistoric times, being readily pointed out by even the most unstarwise wayfarer. As a matter of fact, it is often considered by astronomers to be among the clearest constellations in the winter sky,[6] although it is not visible during summer, when the Sun is too visually close.

The discredited archeological Orion correlation theory postulated a connection between the positions of the Giza pyramids and those of the belt, with the linkage shown to be spurious when placed within the proper historical context.[7]

Belt features

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In this broader view, the belt (the line of three stars in the center) is seen in relation to nearby features in Orion

The names of the three stars that comprise the belt derive from Arabic. All three were once known as Al Niṭhām (النظام) meaning "string of pearls" with spelling variants that include Alnihan and Ainilam,[8] which was suggested by Knobel to be mistakes in transliteration or copy errors.[9]

Alnitak

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Main article: Alnitak

Alnitak (ζ Orionis) is a triple star system at the eastern end of Orion's belt and is 1,260 light-years from the Earth. Alnitak B is a 4th-magnitude B-type star which orbits Alnitak A every 1,500 years. The primary (Alnitak A) is itself a close binary, comprising Alnitak Aa (a blue supergiant of spectral type O9.7 Ibe and an apparent magnitude of 2.0) and Alnitak Ab (a blue subgiant of spectral type B1IV and an apparent magnitude of about 4). Alnitak Aa is estimated to be up to 28 times as massive as the Sun and have a diameter 20 times greater. It is the brightest star of class O in the night sky.[10]

Alnilam

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Main article: Alnilam

Alnilam (ε Orionis) is a singular B0 supergiant, approximately 2,000 light-years away from Earth and magnitude 1.69. It is the 29th-brightest star in the sky and the fourth-brightest in Orion. It is 375,000 times more luminous than the Sun.[11] Its spectrum serves as one of the stable anchor points by which other stars are classified.[citation needed]

Mintaka

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Main article: Mintaka

Mintaka (δ Orionis) is a six-star system at the western end of the Belt,[12] and the star system closest to the celestial equator.[8] It is the nearest massive multiple stellar system, composed of three spectroscopic components.[13] The most luminous individual star is a O9.5 II blue giant. Together, the system has a combined ~250,000 solar luminosity. Mintaka is 1,200 light-years distant, with a visual magnitude of 2.25. The innermost binary has a period of 5.732 days and a semi-major axis of approximately 32 million kilometers (0.22 AU), with the two massive stars eclipsing each other twice per completed orbit as viewed from Sol, from which regular minor dips in brightness arise.[12][13]

References in history and culture

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Dunhuang Star Atlas – Orion
Orion's belt at top left, Orion's sword at bottom right

Richard Hinckley Allen lists many folk names for the Belt of Orion. English ones include: Jacob's Rod or Jacob's Staff; Peter's Staff; the Golden Yard-arm; The L, or Ell; The Ell and Yard; the Yard-stick, and the Yard-wand; the Ellwand; Our Lady's Wand; the Magi / the Three Kings; the Three Marys; or simply the Three Stars.[14]

The passage "Canst thou bind the sweet influences of Pleiades, or loose the bands of Orion?" is found in the Bible's Book of Job[15] and Book of Amos.[16] Tennyson's poem The Princess describes Orion's belt as:

...those three stars of the airy Giant's zone,
That glitter burnished by the frosty dark.[17]

In China's Classic of Poetry, the asterism, under the name "Shen" (参), was paired with Antares, which is known as "Shang" (商), to be a metaphor for two people who could never unite.[18] This might have stemmed from the observation that both Orion's Belt and Antares rise in the east and set in the west, but Antares only rises once Orion's Belt has set and vice versa.[citation needed]

The three stars of the belt are known in Portugal and South America as Las Tres Marías in Spanish, and as "As Três Marias" in Portuguese.[citation needed] They also mark the northern night sky when the Sun is at its lowest point, and were a clear marker for ancient timekeeping. In Mexico they are called the Los Tres Reyes Magos.[19]

In Finnish mythology, the Belt of Orion is called Väinämöisen vyö (Väinämöinen's Belt). The stars which appear to "hang" off the belt form an asterism called Kalevanmiekka (Kaleva's sword).[citation needed] In pre-Christian Scandinavia, the belt was known as Frigg's Distaff (Friggerock) or Freyja's distaff.[20] Similarly Jacob's Staff and Peter's Staff were European biblical derived terms, as were the Three Magi, or the Three Kings. Väinämöinen's Scythe (Kalevala) and Kalevan Sword are terms from Finnish mythology.[21]

The Seri people of northwestern Mexico call the three belt stars Hapj (a name denoting a hunter) which consists of three stars: Hap (mule deer), Haamoja (pronghorn), and Mojet (bighorn sheep). Hap is in the middle and has been shot by the hunter; its blood has dripped onto Tiburón Island.[22]

The Māori people of New Zealand refer to the belt as Tautoru (literally "string of three"), and it is often seen as the stern of the constellation Te Waka o Rangi (the canoe of Rangi), which extends to its prow at Matariki (The Pleiades). The rising of Matariki in the dawn sky marks the Māori New Year in late May or early June.[23]

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See also

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Wikimedia Commons has media related to Orion's Belt.

References

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  1. ^ a b c "Orion Constellation: Facts, location and stars of the hunter". Space.com. 4 November 2021. Archived from the original on 10 March 2022. Retrieved 10 March 2022.
  2. ^ Zack, Malcolm; et al. (2018). Stargazing Under Suburban Skies, A Star-Hopper's Guide. Springer International Publishing. p. 102. ISBN 9783319901169.
  3. ^ Guide, Universe (25 January 2015). "Alnitak / Zeta Orionis Star Facts (Type, Distance, Magnitude, Age, Colour, Location and more) - Universe Guide". www.universeguide.com. Retrieved 18 July 2024.
  4. ^ Guide, Universe (25 January 2015). "Alnitak / Zeta Orionis Star Facts (Type, Distance, Magnitude, Age, Colour, Location and more) - Universe Guide". www.universeguide.com. Retrieved 18 July 2024.
  5. ^ Guide, Universe (25 January 2015). "Mintaka / Delta Orionis Star Facts (Type, Distance, Magnitude, Age, Mass, Colour, Location and more) - Universe Guide". www.universeguide.com. Retrieved 18 July 2024.
  6. ^ "How to Find Orion's Belt in the Night Sky". HowStuffWorks. 1 January 1970. Retrieved 18 July 2024.
  7. ^ Orofino, Vincenzo (28 September 2011). "A quantitative astronomical analysis of the Orion Correlation Theory". arXiv:1109.6266v2 [physics.hist-ph].
  8. ^ a b Allen, Richard Hinckley (1936). Star-names and their meanings (PDF). Creative Media Partners, LLC. pp. 314–15. ISBN 0344214052.
  9. ^ Knobel, E. B. (September 1909). "The name of epsilon Orionis". The Observatory. 32: 357. Bibcode:1909Obs....32..357K.
  10. ^ "Alnitak". Jim Kaler's Stars. University of Illinois at Urbana-Champaign. 2009. Archived from the original on 17 December 2011. Retrieved 28 November 2011.
  11. ^ "Alnilam". Jim Kaler's Stars. University of Illinois at Urbana-Champaign. 2009. Archived from the original on 24 November 2011. Retrieved 28 November 2011.
  12. ^ a b "Mintaka". Jim Kaler's Stars. University of Illinois at Urbana-Champaign. 2009. Archived from the original on 24 November 2011. Retrieved 28 November 2011.
  13. ^ a b Oplištilová, A.; Mayer, P.; Harmanec, P.; Brož, M.; Pigulski, A.; Božić, H.; Zasche, P.; Šlechta, M.; Pablo, H.; Kołaczek-Szymański, P. A.; Moffat, A. F. J.; Lovekin, C. C.; Wade, G. A.; Zwintz, K.; Popowicz, A. (24 January 2023). "Spectrum of the secondary component and new orbital elements of the massive triple star Delta Ori A". Astronomy & Astrophysics. 672: A31. arXiv:2301.10290. doi:10.1051/0004-6361/202245272. ISSN 0004-6361.
  14. ^ Allen, Richard Hinckley. "Star Names – Their Lore and Meaning". Archived from the original on 8 August 2022. Retrieved 19 February 2021.
  15. ^ Job 38:31
  16. ^ Amos 5:8
  17. ^ "Alfred Lord Tennyson's poem: The Princess". Archived from the original on 27 May 2013. Retrieved 11 March 2013.
  18. ^ Lihui Yang, Deming An & Jessica Anderson Turner (2008). Handbook of Chinese Mythology. Oxford University Press. p. 99. ISBN 9780195332636.
  19. ^ "Reyes1". Archived from the original on 15 February 2005. Retrieved 2 April 2011.
  20. ^ Schön, Ebbe. (2004). Asa-Tors hammare, Gudar och jättar i tro och tradition. Fält & Hässler, Värnamo. p. 228.
  21. ^ Allen, Richard Hinckley (1936). Star-names and their meanings. pp. 314–315.
  22. ^ Moser, Mary B.; Stephen A. Marlett (2005). Comcáac quih yaza quih hant ihíip hac: Diccionario seri-español-inglés (PDF) (in Spanish and English). Hermosillo, Sonora and Mexico City: Universidad de Sonora and Plaza y Valdés Editores. Archived (PDF) from the original on 12 April 2019. Retrieved 7 January 2018.
  23. ^ Merton,. E., "Matariki and Māori astronomy with Dr Rangi Matamua Archived 2022-08-08 at the Wayback Machine," The McGuinness Institute, 21 July 2017.
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