Wikipedia

Orionids

The Orionids meteor shower, often shortened to the Orionids, is one of two meteor showers associated with Halley's Comet. The Orionids are so-called because the point they appear to come from, called the radiant, lies in the constellation Orion, but they can be seen over a large area of the sky. The Orionids are an annual meteor shower which last approximately one week in late October. In some years, meteors may occur at rates of 50–70 per hour.[6][7]

Orionids (ORI)
The radiant of the Orionids is located about 10 degrees northeast of Betelgeuse[1]
Discovery dateOctober 1839[2]
Parent body1P/Halley[1]
Radiant
ConstellationOrion (10 degrees northeast of Betelgeuse)[1]
Right ascension06h 21m [3]
Declination 15.6°[3]
Properties
Occurs duringOctober 2 – November 7[1]
Date of peakOctober 21[3]
Velocity66.9[4] km/s
Zenithal hourly rate20[5]
See also: List of meteor showers

Orionid outbursts occurred in 585, 930, 1436, 1439, 1465, and 1623.[8] The Orionids occur at the ascending node of Halley's comet. The ascending node reached its closest distance to Earth around 800 BCE. Currently Earth approaches Halley's orbit at a distance of 0.154 AU (23.0 million km; 14.3 million mi; 60 LD) during the Orionids. The next outburst might be in 2070 as a result of particles trapped in a 2:13 MMR with Jupiter.[8]

History

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Meteor showers first designated "shooting stars" were connected to comets in the 1800s. E.C. Herrick made an observation in 1839 and 1840 about the activity present in the October night skies. A. S. Herschel produced the first documented record that gave accurate forecasts for the next meteor shower.[9] The Orionids meteor shower is produced by Halley's Comet, which was named after the astronomer Edmund Halley and last passed through the inner Solar System in 1986 on its 75–76 year orbit.[10] When the comet passes through the Solar System, the Sun sublimates some of the ice, allowing rock particles to break away from the comet. These particles continue on the comet's trajectory and appear as meteors ("falling stars") when they pass through Earth's upper atmosphere.

The meteor shower radiant is located in Orion about 10 degrees northeast of Betelgeuse.[1] The Orionids normally peak around October 21–22 and are fast meteors that make atmospheric entry at about 66 km/s (150,000 mph).[3] Back in the era of 417 and 585, the Orionids took place around September 24 instead of October 21.[11] Halley's comet is also responsible for creating the Eta Aquariids, which occur each May as a result of the descending node of Halley's comet.[8]

An outburst with a zenithal hourly rate of 100 occurred on 21 October 2006 as a result of Earth passing through the 1266 BCE, 1198 BCE, and 911 BCE meteoroid streams.[12] In 2015, the meteor shower peaked on October 26.[13]

Year Activity Date Range Peak Date ZHRmax
1839 October 8–15[9]
1864 October 18–20[9]
1936 October 19[12]
1981 October 18–21[9] October 23 20
1984 October 21–24[9] October 21–24 (flat maximum)
2006 October 2 — November 7[9][14] October 21–24[14][15] 100 [12]
2007 October 20–24[16] October 21 (predicted)[16] 70[17]
2008 October 15–29[18] October 20–22 (predicted)[18] 39
2009 October 18–25 [9] October 22[19] 45[19]
2010 October 23 38
2011 October 22 33
2012 October 2 — November 7 October 20 and October 23 43[20]
2013 October 22 ~30[21]
2014 October 2 — November 7 October 21 28
2015 October 2 — November 7 October 26 37
2016 October 2 — November 7 October 21[22] 84[13]
2017 October 21 55
2018 October 21 58
2019 October 22 40
2020 October 22 36
2021 October 21 41
2022 October 22 38
2023 October 21 48[13]

* This meteor shower may give double peaks as well as plateaus, and time periods of flat maxima lasting several days.[9]

The radiant of the Orionids is located between the constellations Orion and Gemini (in the southeastern sky before dawn, as viewed from mid-northern latitudes.[9]

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  •  
    An Orionid near the center.
  •  
    A fish-eye view.
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    Two Orionids and the Milky Way.
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    A multicolored Orionid.
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    An Orionid to the left.
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    The brightest meteor, a fireball, leaves a persistent smoky trail drifting in high-altitude winds, which is seen on the right side of the image.

See also

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References

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  1. ^ a b c d e Robert Lunsford (2023-10-09). "Viewing the Orionid Meteor Shower in 2023". International Meteor Organization (IMO). Retrieved 2023-10-14. (JPG)
  2. ^ Jenniskens, Peter (2006), Meteor Showers And Their Parent Comets, Cambridge University Press, p. 9, ISBN 0521853494.
  3. ^ a b c d "2023 Meteor Shower List". American Meteor Society (AMS). Retrieved 2023-09-10.
  4. ^ Kero, J.; et al. (October 2011), "First results from the 2009–2010 MU radar head echo observation programme for sporadic and shower meteors: the Orionids 2009", Monthly Notices of the Royal Astronomical Society, 416 (4): 2550–2559, Bibcode:2011MNRAS.416.2550K, doi:10.1111/j.1365-2966.2011.19146.x.
  5. ^ Rendtel, Jürgen (2008), "The Orionid meteor shower observed over 70 years", in Trigo-Rodríguez, J. M.; Rietmeijer, F. J. M.; Llorca, Jordi; Janches, Diego (eds.), Advances in Meteoroid and Meteor Science, Springer, pp. 106–109, Bibcode:2008amms.book.....T, ISBN 978-0387784182.
  6. ^ "IMO Meteor Shower Calendar 2009". The International Meteor Organization. 1997–2009. Retrieved 2009-10-22.
  7. ^ "Orionids Meteor Shower Lights Up the Sky". PhysOrg.com. 2003–2009. Retrieved 2009-10-21.
  8. ^ a b c Egal, A.; Brown, P. G.; Rendtel, J.; Campbell-Brown, M.; Wiegert, P. (2020). "Activity of the Eta-Aquariid and Orionid meteor showers". Astronomy & Astrophysics. 640 (A58): A58. arXiv:2006.08576. Bibcode:2020A&A...640A..58E. doi:10.1051/0004-6361/202038115.
  9. ^ a b c d e f g h i "Orionid". Observing the Orionids. Meteor Showers Online. Archived from the original on 2018-07-11. Retrieved 2009-10-21.
  10. ^ Phillips, Dr. Tony (2009-10-19). "NASA – The 2009 Orionid Meteor Shower". NASA. Archived from the original on 2009-10-22. Retrieved 2009-10-19.
  11. ^ Kinsman, J. H.; Asher, D. J. (2020). "Orbital dynamics of highly probable but rare Orionid outbursts possibly observed by the ancient Maya". Monthly Notices of the Royal Astronomical Society. 493 (1): 551–558. arXiv:2002.00106. doi:10.1093/mnras/staa249.(Table 3)
  12. ^ a b c Sato, Mikiya; Watanabe, Jun-ichi (2007). "Origin of the 2006 Orionid Outburst". Publications of the Astronomical Society of Japan. 59 (4): L21–L24. doi:10.1093/pasj/59.4.L21.
  13. ^ a b c MeteorFlux 2.3 (Select Shower: ORI, uncheck "Use temporary database", select year (such as 2016) and click "Create graph")
  14. ^ a b "October to December 2006". The International Meteor Organization –. 1997–2007. Archived from the original on 2009-11-02. Retrieved 2009-10-22.
  15. ^ Stone, Wes. "2006 Orionid Meteor Shower Surprise!" (PDF). Sky tour. Retrieved 2009-10-22.
  16. ^ a b Handwerk, Brian (October 17, 2009). ""Old Faithful" Orionid Meteor Shower Peaks This Weekend". r National Geographic News. Archived from the original on October 19, 2007. Retrieved 2009-10-22.
  17. ^ Orionids 2007: visual data quicklook. imo.net
  18. ^ a b "Orionids Meteor Shower 2008 of October". Meteor. October 15, 2008. Retrieved 2009-10-21.
  19. ^ a b Orionids 2009. imo.net
  20. ^ Orionids 2012: visual data quicklook. imo.net
  21. ^ "2013 Orionids Radio results". RMOB. Retrieved 2014-08-13.
  22. ^ "Look for Orionid meteors this month | Astronomy Essentials". EarthSky. Retrieved 2017-10-16.
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