Orionids

The Orionids meteor shower, often shortened to the Orionids, is the most prolific meteor shower 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.[5][6]

Orionids (ORI)
Discovery dateOctober 1839[1]
Parent body1P/Halley[2]
Radiant
ConstellationOrion (near Betelgeuse)
Right ascension06h 24m [2]
Declination+15°[2]
Properties
Occurs duringOctober 2 – November 7[2]
Date of peakOctober 21[2]
Velocity66.9[3] km/s
Zenithal hourly rate20[4]

History

Meteor showers first designated "shooting stars" were connected to comets in the 1800s.[7] 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.[8] 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- to 76-year orbit.[9] 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.[7][10] Halley's comet is also responsible for creating the Eta Aquariids, which occur each May.[10]

Year Activity Date Range Peak Date ZHRmax
1839 October 8–15[8]
1864 October 18–20[8]
1981 October 18–21[8] October 23 20
1984 October 21–24[8] October 21–24 (flat maximum)
2006 October 2 — November 7[8][11] October 21–24[11][12] 23 with peaks at 67
2007 October 20–24[13] October 21 (predicted)[13] 70[14]
2008 October 15–29[10] October 20–22 (predicted)[10] 39
2009 October 18–25 [8] October 22[15][16][17] 45[15]
2010 October 23 38
2011 October 22 33
2012 October 2 — November 7 October 20 and October 23 43[18]
2013 October 22 ~30[19]
2014 October 2 — November 7 October 21 20?[20]
2015 October 2 — November 7 October 20–21[21] N/A
2016 October 2 — November 7 October 21[22] ~10–20

* This meteor shower may give double peaks as well as plateaus, and time periods of flat maxima lasting several days.[8]

Meteor shower and location
Map of the night sky showing the constellation Orion and Betelgeuse and a portion of the Gemini constellation

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.[23][24] The most active time of the meteor shower was stated by Telegraph.co.uk to be in the early morning of October 21, 2009 6 a.m. Eastern Standard Time in the United States or 11 a.m. in the United Kingdom.[25] Universe Today reported that the meteor shower arrived at 140,000 miles (230,000 km) per hour on the morning of the 21st when showing was predicted to be at its height, however compared to previous showers in years past, the trail of 2009 appeared narrower without branching out.[26] Observers observing the small meteor "Halleyids" at the Marshall Space Flight Center in Alabama saw streaks radiating in all directions with the naked eye.[27]

  • An Orionid near the center.
  • A fish-eye view.
  • Two Orionids and the Milky Way.
  • A multicolored Orionid.
  • An Orionid to the left.
  • 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

References
  1. Jenniskens, Peter (2006), Meteor Showers And Their Parent Comets, Cambridge University Press, p. 9, ISBN 0521853494.
  2. Moore, Patrick; Rees, Robin (2011), Patrick Moore's Data Book of Astronomy (2nd ed.), Cambridge University Press, p. 275, ISBN 978-0-521-89935-2.
  3. 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.
  4. 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.
  5. "IMO Meteor Shower Calendar 2009". The International Meteor Organization. 1997–2009. Retrieved 2009-10-22.
  6. "Orionids Meteor Shower Lights Up the Sky". PhysOrg.com. 2003–2009. Retrieved 2009-10-21.
  7. Jaggard, Victoria (1996–2009). "Orionids Meteor Shower Starts This Weekend". National Geographic News. National Geographic Society. Retrieved 2009-10-21.
  8. "Orionid". Observing the Orionids. Meteor Showers Online. Archived from the original on 2018-07-11. Retrieved 2009-10-21.
  9. 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.
  10. "Orionids Meteor Shower 2008 of October". Meteor. October 15, 2008. Retrieved 2009-10-21.
  11. "October to December 2006". The International Meteor Organization –. 1997–2007. Archived from the original on 2009-11-02. Retrieved 2009-10-22.
  12. Stone, Wes. "2006 Orionid Meteor Shower Surprise!" (PDF). Sky tour. Retrieved 2009-10-22.
  13. Handwerk, Brian (October 17, 2009). ""Old Faithful" Orionid Meteor Shower Peaks This Weekend". r National Geographic News. Retrieved 2009-10-22.
  14. Orionids 2007: visual data quicklook. imo.net
  15. Orionids 2009. imo.net
  16. Jaggard, Victoria (October 20, 2009). "2009 Orionid Meteor Shower Peak Begins". National Geographic News. Retrieved 2009-10-20.
  17. French, John. "Abrams Planetarium Night Sky Notes". Retrieved 2009-10-21.
  18. Orionids 2012: visual data quicklook. imo.net
  19. "2013 Orionids Radio results". RMOB. Retrieved 2014-08-13.
  20. "Meteor Shower Calendar | IMO | Page 2014". IMO. 2014-06-20. Retrieved 2017-10-16.
  21. "2017 Orionid Meteor Shower". Timeanddate.com. Retrieved 2017-10-16.
  22. "Look for Orionid meteors this month | Astronomy Essentials". EarthSky. Retrieved 2017-10-16.
  23. "Observing the Orionids". Meteor Showers Online. Archived from the original on 2018-07-11. Retrieved 2009-10-19.
  24. "Okanagan Observatory's Notes". Okanagan Observatory. 2009. Retrieved 2009-10-21.
  25. Collins, Nick (October 21, 2009). "Meteor shower: Orionids reach peak The Orionid meteor shower, a trail of debris left in space by Halley's Comet, was at its most intense in the early hours of Wednesday". Telegraph.co.uk. Telegraph Media Group Limited. Retrieved 2009-10-21.
  26. Piotner, Tammy (2009-10-21). "The Orionid Meteor Shower – What Did You See?". Universe Today. Archived from the original on October 24, 2009. Retrieved 2009-10-21.
  27. "Spaceweather.com Time Machine". spaceweather.com. Retrieved 2020-08-13.
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