Wikipedia

209P/LINEAR

209P/LINEAR is a periodic comet with an orbital period of 5.1 years. The comet has extremely low activity for its size and is probably in the process of evolving into an extinct comet.[6]

209P/LINEAR
Discovery
Discovered byLINEAR
1.0-m reflector[1]
Discovery date3 February 2004 (asteroidal)
30 March 2004 (tail)
Designations
2004 CB
Orbital characteristics
Epoch2014-May-23
(JD 2456800.5)[2]
Aphelion4.952 AU (Q)
Perihelion0.9695 AU (q)
Semi-major axis2.961 AU (a)
Eccentricity0.67258
Orbital period5.09 yr
Inclination21.243°
Last perihelion2019-Jun-12[2]
2014-May-06[3]
2009-Apr-15[3]
Next perihelion2024-Jul-14[4]
Earth MOID0.05 AU (7,500,000 km)[5]
Physical characteristics
Dimensions3.9 × 2.7 × 2.6 km [6]
10.9 hours[7]
Comet total
magnitude (M1)		18.1[5]

Observational history

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The 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.[8] It was given the permanent number 209P on 12 December 2008 as it was the second observed appearance of the comet.[9] Prediscovery images of the comet, dating back to December 2003, were found during 2009.[8]

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,[5] but only brightened to about apparent magnitude 12.[10] The 2014 Earth approach was the 9th closest known comet approach to Earth.[11] The close approach allowed the comet nucleus to be imaged by Arecibo, producing the most detailed radar image of a comet nucleus to that date.[12] The radar imaging showed the comet nucleus is elongated and about 2.4 km by 3 km in size,[12] later refined to 3.9 × 2.7 × 2.6 km.[6] No evidence of large dust particles were detected in the coma.[7] The comet also had very low water production, (2.5±0.2)×1025 mol/s, from an active area measuring just 0.007 km².[6]

209P/LINEAR was recovered on 31 December 2018 at magnitude 19.2 by Hidetaka Sato.[13]

Associated meteor showers

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Preliminary results by Esko Lyytinen and Peter Jenniskens, later confirmed by other researchers, predicted[14][15][16] 209P/LINEAR might a 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.[14] All the trails from the comet from 1803 through 1924 were expected to intersect Earth's orbit during May 2014.[14] 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.[16] The 2014 Camelopardalids only generated 10–15 visual meteors per hour.[17][18] But the expected radiant and date of visual maximum were correctly predicted.[18] The shower peaked around 6h UT on 24 May 2014.[18] The Canadian Meteor Orbit Radar (CMOR) detected the shower using HF/VHF radar echos but the particles were too small for visual detection. Earth encountered the 1939 stream around 24 May 2019 8h UT with a ZHR of ~5. The Eta Aquariids also occur at this time of year.[19]

209P/LINEAR may also be the source of the weak 6–14 June meteor shower "sigma Ursae Majorids" (SIM #677).[11]

References

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  1. ^ a b "IAUC 8314: P/2004 CB; 2004ba, 2004bb". IAU Central Bureau for Astronomical Telegrams. 2004-03-31. Retrieved 2012-10-03.
  2. ^ a b "209P/LINEAR Orbit". Minor Planet Center. Retrieved 2014-05-09.
  3. ^ a b c Syuichi Nakano (2011-10-31). "209P/LINEAR (NK 2142)". OAA Computing and Minor Planet Sections. Retrieved 2012-10-03.
  4. ^ "Horizons Batch for 209P/LINEAR on 2024-Jul-14" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 2023-07-06. (JPL#141/Soln.date: 2023-Feb-13)
  5. ^ a b c "JPL Close-Approach Data: 209P/LINEAR" (last observation: 2014-05-26; arc: 10.48 years). Retrieved 2012-10-03.
  6. ^ a b c d Schleicher, David G.; knight, Matthew m. (27 September 2016). "The Extremely Low Activity Comet 209P/Linear During ITS Extraordinary Close Approach in 2014". The Astronomical Journal. 152 (4): 89. arXiv:1605.01705. Bibcode:2016AJ....152...89S. doi:10.3847/0004-6256/152/4/89.
  7. ^ a b Howell, Ellen S.; Nolan, Michael C.; Taylor, Patrick A.; Springmann, Alessondra; Rodriguez-Ford, Linda; Zambrano-Marin, Luisa F.; Benner, Lance A.; Brozovic, Marina; Giorgini, Jon D.; Hergenrother, Carl (1 November 2014). "Radar images of Comet 209P/LINEAR: Constraints on shape and rotation". AAS/Division for Planetary Sciences Meeting Abstracts. 46: 209.24. Bibcode:2014DPS....4620924H.
  8. ^ a b Gary W. Kronk. "209P/LINEAR". Cometography. Archived from the original on 2014-05-03. Retrieved 2014-05-03.
  9. ^ "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)
  10. ^ Alan Hale. "455. COMET 209P/LINEAR P/2008 X2". Earthrise Institute (Southwest Institute for Space Research). Retrieved 2012-10-03.
  11. ^ a b Peter Jenniskens. "May Camelopardalids". SETI Institute. Retrieved 2014-05-25.
  12. ^ a b "Arecibo Observatory Sees Comet 209P/LINEAR". Universities Space Research Association (USRA). 2014-05-29. Archived from the original on 2014-05-29. Retrieved 2014-05-29.
  13. ^ "Comets Waiting for First Observation". www.aerith.net.
  14. ^ a b c "The next big meteor shower". IMCCE. Archived from the original on 2012-10-06. Retrieved 2012-10-03.
  15. ^ "209P-ids 2014: prediction of activity". Archived from the original on 2014-04-14. Retrieved 2014-04-13.
  16. ^ a b Wiegert, Paul A.; Quanzhi Ye (2013). "Will Comet 209P/LINEAR Generate the Next Meteor Storm?". Monthly Notices of the Royal Astronomical Society. 437 (4): 3283–3287. arXiv:1311.0235. Bibcode:2014MNRAS.437.3283Y. doi:10.1093/mnras/stt2127.
  17. ^ "Camelopardalids meteor shower a bust, but not a surprise". The Washington Post. 2014-05-24. 10:07AM. Retrieved 2014-05-24.
  18. ^ a b c "Camelopardalids 2014: First Results". International Meteor Organization. Archived from the original on 2014-05-25. Retrieved 2014-05-25.
  19. ^ "Meteor Activity Outlook for May 24–30, 2014". Archived from the original on 2014-05-25. Retrieved 2014-05-24.
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Numbered comets
Previous
208P/McMillan 		209P/LINEAR Next
210P/Christensen
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