209P/LINEAR

209P/LINEAR
Discovery
Discovered by LINEAR
1.0-m reflector[1]
Discovery date 3 February 2004 (asteroidal)
30 March 2004 (tail)
Alternative
designations		 2004 CB
Orbital characteristics A
Epoch 2014-May-23
(JD 2456800.5)[2]
Aphelion 4.952 AU (Q)
Perihelion 0.9695 AU (q)
Semi-major axis 2.961 AU (a)
Eccentricity 0.67258
Orbital period 5.09 yr
Inclination 21.243°
Last perihelion 2014-May-06[3]
2009-Apr-15[3]
Next perihelion 2019-Jun-12[2]

209P/LINEAR is a periodic comet discovered on 3 February 2004 by Lincoln Near-Earth Asteroid Research (LINEAR) using a 1.0-metre (39 in) reflector.[1] Initially it was observed without a coma and named 2004 CB as a minor planet or asteroid, but in March 2004 Robert H. McNaught observed a comet tail which confirmed it as a comet.[4] It was given the permanent number 209P on 12 December 2008 as it was the second observed appearance of the comet.[5] Prediscovery images of the comet, dating back to December 2003, were found during 2009.[4] Arecibo imaging in 2014 showed the comet nucleus is peanut shaped and about 2.4 km in diameter.[6][7] The comet has extremely low activity for its size and is probably in the process of evolving into an extinct comet.

2014 passage

209P/LINEAR came to perihelion (closest approach to the Sun) on 6 May 2014.[3] On 29 May 2014 the comet passed 0.0554 AU (8,290,000 km; 5,150,000 mi) from Earth,[8] but only brightened to about apparent magnitude 12.[9] The 2014 Earth approach was the 9th closest known comet approach to Earth.[10]

Associated meteor showers

Preliminary results by Esko Lyytinen and Peter Jenniskens, later confirmed by other researchers, predicted[11][12][13] 209P/LINEAR might generate the next big meteor shower which would come from the constellation Camelopardalis on the night of 23/24 May 2014. It was possible that there could be 100 to 400 meteors per hour.[11] All the trails from the comet from 1803 through 1924 were expected to intersect Earth's orbit during May 2014.[11] The peak activity was expected to occur around 24 May 2014 7h UT when dust trails produced from past returns of the comet could pass 0.0002 AU (30,000 km; 19,000 mi) from Earth.[13] The 2014 Camelopardalids only generated 10–15 visual meteors per hour.[14][15] But the expected radiant and date of visual maximum were correctly predicted.[15] The shower peaked around 6h UT on 24 May 2014.[15] The Canadian Meteor Orbit Radar (CMOR) detected the shower using HF/VHF radar echos but the particles were too small for visual detection. Earth will encounter the 1939 stream around 24 May 2019 8h UT with a ZHR of ~5. The Eta Aquariids also occur at this time of year.[16]

209P/LINEAR may also be the source of the weak 6–14 June meteor shower "sigma Ursae Majorids" (SIM #677).[10]

References

  1. 1 2 "IAUC 8314: P/2004 CB; 2004ba, 2004bb". IAU Central Bureau for Astronomical Telegrams. 2004-03-31. Retrieved 2012-10-03.
  2. 1 2 "209P/LINEAR Orbit". Minor Planet Center. Retrieved 2014-05-09.
  3. 1 2 3 Syuichi Nakano (2011-10-31). "209P/LINEAR (NK 2142)". OAA Computing and Minor Planet Sections. Retrieved 2012-10-03.
  4. 1 2 Gary W. Kronk. "209P/LINEAR". Cometography. Retrieved 2014-05-03.
  5. ↑ "IAUC 9005: COMET P/2008 X4 = P/2003 K2 (CHRISTENSEN); 208P; V5580 Sgr". IAU Central Bureau for Astronomical Telegrams. 2008-12-12. Retrieved 2012-10-03. (password required)
  6. ↑ "Arecibo Observatory Sees Comet 209P/LINEAR". Universities Space Research Association (USRA). 2014-05-29. Retrieved 2014-05-29.
  7. ↑ https://twitter.com/AreciboRadar/status/469988750110777345
  8. ↑ "JPL Close-Approach Data: 209P/LINEAR" (last observation: 2014-05-26; arc: 10.48 years). Retrieved 2012-10-03.
  9. ↑ Alan Hale. "455. COMET 209P/LINEAR P/2008 X2". Earthrise Institute (Southwest Institute for Space Research). Retrieved 2012-10-03.
  10. 1 2 Peter Jenniskens. "May Camelopardalids". SETI Institute. Retrieved 2014-05-25.
  11. 1 2 3 "The next big meteor shower". IMCCE. Retrieved 2012-10-03.
  12. ↑ "209P-ids 2014: prediction of activity". Retrieved 2014-04-13.
  13. 1 2 Wiegert, Paul A.; Quanzhi Ye (2013). "Will Comet 209P/LINEAR Generate the Next Meteor Storm?". Monthly Notices of the Royal Astronomical Society. arXiv:1311.0235. Bibcode:2014MNRAS.437.3283Y. doi:10.1093/mnras/stt2127.
  14. ↑ "Camelopardalids meteor shower a bust, but not a surprise". The Washington Post. 2014-05-24. 10:07AM. Retrieved 2014-05-24.
  15. 1 2 3 "Camelopardalids 2014: First Results". International Meteor Organization. Retrieved 2014-05-25.
  16. ↑ Meteor Activity Outlook for May 24-30, 2014

External links

Periodic comets (by number)
Previous
208P/McMillan 		209P/LINEAR Next
210P/Christensen
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