Ophiuchus

Source: Wikipedia, the free encyclopedia.

Ophiuchus
Constellation
11th)
Main stars10
Bayer/Flamsteed
stars
65
Stars brighter than 3.00m5
Stars within 10.00 pc (32.62 ly)11
Brightest starα Oph (Rasalhague) (2.08m)
Messier objects7
Meteor showers
Bordering
constellations
Visible at latitudes between +80° and −80°.
Best visible at 21:00 (9 p.m.) during the month of July.

Ophiuchus (/ˌɒfiˈjuːkəs/) is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek ὀφιοῦχος (ophioûkhos), meaning "serpent-bearer", and it is commonly represented as a man grasping a snake. The serpent is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. An old alternative name for the constellation was Serpentarius (/ˌsɜːrpənˈtɛəriəs/).[1]

Location

Rho Ophiuchi, shown with a surrounding bluish cloud slightly above a pentagon of stars in Scorpius, with the main band of the Milky Way much further to the left

Ophiuchus lies between

Rasalhague, its brightest star, lies near the northern edge of Ophiuchus at about +12° 30′ declination.[5] The constellation extends southward to −30° declination. Segments of the ecliptic within Ophiuchus are south of −20° declination.[citation needed
]

In contrast to Orion, from November to January (summer in the Southern Hemisphere, winter in the Northern Hemisphere), Ophiuchus is in the daytime sky and thus not visible at most latitudes. However, for much of the Arctic Circle in the Northern Hemisphere's winter months, the Sun is below the horizon even at midday. Stars (and thus parts of Ophiuchus, especially Rasalhague) are then visible at twilight for a few hours around local noon, low in the south. In the Northern Hemisphere's spring and summer months, when Ophiuchus is normally visible in the night sky, the constellation is actually not visible, because the midnight sun obscures the stars at those times and places in the Arctic. In countries close to the equator, Ophiuchus appears overhead in June around midnight and in the October evening sky.[citation needed]

Features

Stars

The brightest stars in Ophiuchus include

K-type main sequence star.[9] The primary is a rapid rotator[10] with an inclined axis of rotation.[11] Eta Ophiuchi is a binary system.[12] Other bright stars in the constellation include β Ophiuchi, Cebalrai ("dog of the shepherd")[13] and λ Ophiuchi, or Marfik ("the elbow").[14] Beta Ophiuchi is an evolved red giant star that is slightly more massive than the Sun.[15][16] Lambda Ophiuchi is a binary star system with the primary being more massive and luminous than the Sun.[17][18]

RS Ophiuchi is part of a class called recurrent novae, whose brightness increase at irregular intervals by hundreds of times in a period of just a few days. It is thought to be at the brink of becoming a type-1a supernova.[19] It erupts around every 15 years and usually has a magnitude of around 5.0 during eruptions, most recently in 2021.[20][21]

nearest stars to the Solar System (the only stars closer are the Alpha Centauri binary star system and Proxima Centauri), lies in Ophiuchus. It is located to the left of β and just north of the V-shaped group of stars in an area that was once occupied by the now-obsolete constellation of Taurus Poniatovii (Poniatowski's Bull). It is thought that an exoplanet orbits around the star,[22] but later studies have refuted this claim.[23] In 1998, an intense flare was observed.[24][25] The star has also been a target of plans for interstellar travel such as Project Daedalus.[26][27] In 2005, astronomers using data from the Green Bank Telescope discovered a superbubble so large that it extends beyond the plane of the galaxy.[28] It is called the Ophiuchus Superbubble
.

In April 2007,

supernova of 1604 was first observed on 9 October 1604, near θ Ophiuchi. Johannes Kepler saw it first on 16 October and studied it so extensively that the supernova was subsequently called Kepler's Supernova. He published his findings in a book titled De stella nova in pede Serpentarii (On the New Star in Ophiuchus's Foot). Galileo used its brief appearance to counter the Aristotelian dogma that the heavens are changeless. It was a Type Ia supernova[30] and the most recent Milky Way supernova visible to the unaided eye.[31] In 2009 it was announced that GJ 1214, a star in Ophiuchus, undergoes repeated, cyclical dimming with a period of about 1.5 days consistent with the transit of a small orbiting planet.[32] The planet's low density (about 40% that of Earth) suggests that the planet may have a substantial component of low-density gas—possibly hydrogen or steam.[33] The proximity of this star to Earth (42 light years) makes it a tempting target for further observations.[according to whom?] The host star emits X-rays which could have removed mass from the exoplanet.[34] In April 2010, the naked-eye star ζ Ophiuchi was occulted by the asteroid 824 Anastasia.[35][36][37]

  • The constellation Ophiuchus as it can be seen by naked eye[38]
    The constellation Ophiuchus as it can be seen by naked eye[38]
  • Johannes Kepler's drawing depicting the location of the stella nova in the foot of Ophiuchus
    Johannes Kepler's drawing depicting the location of the stella nova in the foot of Ophiuchus
  • Hercules and Ophiuchus, 1602 by Willem Blaeu
    Hercules and Ophiuchus, 1602 by Willem Blaeu

Deep-sky objects

Infrared light view of Rho Ophiuchi molecular cloud complex from NASA
Photo from Rogelio Bernal Andreo of the Rho Ophiuchi molecular cloud complex

Ophiuchus contains several

M107, as well as the nebula
IC 4603-4604.

RR Lyrae variables[45] and has two generations of stars with different element abundances.[46] M107 is also rich in variable stars.[47]

The unusual

In 2006, a new nearby

Ursa Major Moving Group, but 7 times more distant (approximately 170 parsecs away). Mamajek 2 appears to have formed in the same star-forming complex as the NGC 2516 cluster roughly 135 million years ago.[51]

Barnard 68 is a large dark nebula, located 410 light-years from Earth. Despite its diameter of 0.4 light-years, Barnard 68 only has twice the mass of the Sun, making it both very diffuse and very cold, with a temperature of about 16 kelvins. Though it is currently stable, Barnard 68 will eventually collapse, inciting the process of star formation. One unusual feature of Barnard 68 is its vibrations, which have a period of 250,000 years. Astronomers speculate that this phenomenon is caused by the shock wave from a supernova.[48] Barnard 68 has blocked thousands of stars visible at other wavelengths[52] and the distribution of dust in Barnard 68 has been mapped.[53][54]

The space probe

κ Ophiuchi at right ascension 17h 13m and declination +12° 25’ (July 2020).[55]

In November 2022, the USA's

light years from the Sun.[56]

History and mythology

There is no evidence of the constellation preceding the classical era, and in Babylonian astronomy, a "Sitting Gods" constellation seems to have been located in the general area of Ophiuchus. However, Gavin White proposes that Ophiuchus may in fact be remotely descended from this Babylonian constellation, representing Nirah, a serpent-god who was sometimes depicted with his upper half human but with serpents for legs.[57]

The earliest mention of the constellation is in Aratus, informed by the lost catalogue of Eudoxus of Cnidus (4th century BCE):[58]

To the Phantom's back the Crown is near, but by his head mark near at hand the head of Ophiuchus, and then from it you can trace the starlit Ophiuchus himself: so brightly set beneath his head appear his gleaming shoulders. They would be clear to mark even at the midmonth moon, but his hands are not at all so bright; for faint runs the gleam of stars along on this side and on that. Yet they too can be seen, for they are not feeble. Both firmly clutch the Serpent, which encircles the waist of Ophiuchus, but he, steadfast with both his feet well set, tramples a huge monster, even the Scorpion, standing upright on his eye and breast. Now the Serpent is wreathed about his two hands – a little above his right hand, but in many folds high above his left.[59]

To the

Oracle of Delphi.[60]

Later myths identified Ophiuchus with

Uranometry, 10th century), the constellation was known as Al-Ḥawwa', "the snake-charmer".[62]

zodiacal constellation at least as regards his feet.[63] This arrangement has been taken as symbolic in later literature and placed in relation to the words spoken by God to the serpent in the Garden of Eden (Genesis 3:15).[64]

  • Ophiuchus in a manuscript copy of Azophi's Uranometry, 18th century copy of a manuscript prepared for Ulugh Beg in 1417 (note that as in all pre-modern star charts, the constellation is mirrored, with Serpens Caput on the left and Serpens Cauda on the right).
    Ophiuchus in a manuscript copy of
    Serpens Cauda
    on the right).
  • Ophiuchus holding the serpent, Serpens, as depicted in Urania's Mirror, a set of constellation cards published in London c. 1825. Above the tail of the serpent is the now-obsolete constellation Taurus Poniatovii while below it is Scutum.
    Ophiuchus holding the serpent, Serpens, as depicted in Urania's Mirror, a set of constellation cards published in London c. 1825. Above the tail of the serpent is the now-obsolete constellation Taurus Poniatovii while below it is Scutum.

Zodiac

Ophiuchus is one of the thirteen constellations that cross the

Babylonians originally developed the Zodiac.[71][72]

Citations

  1. ^ "Star Tales – Ophiuchus". Retrieved 25 June 2021.
  2. ^ Ford, Dominic. "The Constellation Ophiuchus – In-The-Sky.org". in-the-sky.org. Retrieved 23 June 2018.
  3. .
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  5. ^ Ford, Dominic. "Rasalhague (Star)". in-the-sky.org. Retrieved 23 June 2018.
  6. ).
  7. CDS. ID V/50
    .
  8. .
  9. .
  10. ^ Chartrand, at p. 170.
  11. S2CID 14531031
  12. .
  13. .
  14. ^ "Star 'soon to become supernova'". BBC News. 23 July 2006.
  15. ^ "[vsnet-alert 26131] Outburst of RS Ophiuchi". ooruri.kusastro.kyoto-u.ac.jp. Retrieved 9 August 2021.
  16. ^ "ATel #14834: Fermi-LAT Gamma-ray Detection of the Recurrent Nova RS Oph". ATel. Retrieved 9 August 2021.
  17. (PDF) from the original on 26 March 2019.
  18. .
  19. .
  20. .
  21. on 20 October 2007. Retrieved 15 August 2006.
  22. ^ Darling, David (July 2005). "Daedalus, Project". The Encyclopedia of Astrobiology, Astronomy, and Spaceflight. Archived from the original on 31 August 2006. Retrieved 10 August 2006.
  23. PhysOrg.com
    . 13 January 2006. Retrieved 4 July 2008.
  24. ^ "Molecular Oxygen Detected for the First Time in the Interstellar Medium". Retrieved 28 September 2016.
  25. .
  26. ^ "Kepler's Supernova: Recently Observed Supernova". Universe for Facts. Archived from the original on 4 January 2019. Retrieved 21 December 2014.
  27. S2CID 4360404
    .
  28. .
  29. . L11.
  30. ^ "Asteroid To Hide Naked-Eye Star". 31 March 2010. Retrieved 17 July 2019.
  31. ^ "Asteroid To Hide Bright Star". 31 March 2010. Retrieved 17 July 2019.
  32. ^ "(824) Anastasia / HIP 81377 event on 2010 Apr 06, 10:21 UT". Archived from the original on 17 July 2019. Retrieved 17 July 2019.
  33. ^ "Ophiuchus, the Serpent Bearer – Constellations – Digital Images of the Sky".
  34. .
  35. ^ Levy 2005, pp. 153–54.
  36. .
  37. .
  38. .
  39. .
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  41. , 250.22.
  42. ^ .
  43. ^ Komossa, Stefanie; Burwitz, Vadim; Hasinger, Guenther; Predehl, Peter; et al. (2003). "Discovery of a Binary Active Galactic Nucleus in the Ultraluminous Infrared Galaxy NGC 6240 Using Chandra".
    S2CID 16697327
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  45. .
  46. ^ "The Dark Cloud B68 at Different Wavelengths". European Southern Observatory. Retrieved 30 January 2012.
  47. ^ Alves, João; Lada, Charles; Lada, Elizabeth (March 2001). "Seeing the light through the dark" (PDF). The Messenger. 103: 15–20. .
  48. ^ Alves, João F.; Lada, Charles J.; Lada, Elizabeth A. (January 2001). "Internal structure of a cold dark molecular cloud inferred from the extinction of background starlight". Nature. 409 (6817): 159–161.
    S2CID 4318459
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  49. ^ Coordinates available at The Sky Live.
  50. National Optical-Infrared Astronomy Research Laboratory
    ), 2022-11-04
  51. ^ White, Gavin; Babylonian Star-lore, Solaria Pubs, 2008, p. 187f
  52. ^ Liddell, Henry George; Scott, Robert. "ὀφιοῦχος". A Greek-English Lexicon. perseus.tufts.edu.
  53. ^ translation by Mair, Alexander W.; & Mair, Gilbert R.; Loeb Classical Library, volume 129, William Heinemann, London, 1921 theoi.com
  54. ^ .
  55. ^ Hyginus, Astronomica 2, 14, Latin Mythography, 2nd century AD
  56. ^ "Snake-Charmer". Brickthology. Retrieved 1 February 2022.
  57. ^ "Manuscript reproduction". Archived from the original on 6 May 2019. Retrieved 17 July 2019.
  58. ^ Maunder, Edward Walter; Astronomy of the Bible, 1908, p. 164f
  59. ^ Shapiro, Lee T. "Constellations in the zodiac", in The Space Place (NASA, last updated 22 July 2011)
  60. ^ "Ophiuchus, 13th constellation of zodiac". Earth Sky. Retrieved 19 July 2019.
  61. ^ Gleason, Edward. "Why is the vernal equinox called the "First Point of Aries" when the Sun is actually in Pisces on this date? | Planetarium". University of Southern Maine. Retrieved 25 March 2022.
  62. ^ Campbell, Tina (15 July 2020). "Has your star sign changed following the discovery of a 'new' Zodiac sign?". Metro. Retrieved 29 April 2021.
  63. ^ "Ophiuchus – a 13th Zodiac Sign? No!". Astrology Club. 2 March 2016. Retrieved 18 October 2016.
  64. ^ "Born under the sign of Ophiuchus?". EarthSky.org. 16 August 2021.
  65. .
  66. ^ Redd, Nola Taylor. "Constellations: The Zodiac Constellation Names". space.com. Retrieved 3 August 2012.

See also

  • Ophiuchus (Chinese astronomy)

References

External links