|Discovery date||3 February 2004 (asteroidal)|
30 March 2004 (tail)
|Orbital characteristics A|
|Aphelion||4.952 AU (Q)|
|Perihelion||0.9695 AU (q)|
|Semi-major axis||2.961 AU (a)|
|Orbital period||5.09 yr|
|Earth MOID||0.05 AU (7,500,000 km)|
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. 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. It was given the permanent number 209P on 12 December 2008 as it was the second observed appearance of the comet. Prediscovery images of the comet, dating back to December 2003, were found during 2009. Arecibo imaging in 2014 showed the comet nucleus is peanut shaped and about 2.4 km in diameter. The comet has extremely low activity for its size and is probably in the process of evolving into an extinct comet.
209P/LINEAR was recovered on 31 December 2018 at magnitude 19.2 by Hidetaka Sato, but not officially announced yet.
209P/LINEAR came to perihelion (closest approach to the Sun) on 6 May 2014. On 29 May 2014 the comet passed 0.0554 AU (8,290,000 km; 5,150,000 mi) from Earth, but only brightened to about apparent magnitude 12. The 2014 Earth approach was the 9th closest known comet approach to Earth.
Associated meteor showers
Preliminary results by Esko Lyytinen and Peter Jenniskens, later confirmed by other researchers, predicted 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. All the trails from the comet from 1803 through 1924 were expected to intersect Earth's orbit during May 2014. 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. The 2014 Camelopardalids only generated 10–15 visual meteors per hour. But the expected radiant and date of visual maximum were correctly predicted. The shower peaked around 6h UT on 24 May 2014. 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.
209P/LINEAR may also be the source of the weak 6–14 June meteor shower "sigma Ursae Majorids" (SIM #677).
- "IAUC 8314: P/2004 CB; 2004ba, 2004bb". IAU Central Bureau for Astronomical Telegrams. 2004-03-31. Retrieved 2012-10-03.
- "209P/LINEAR Orbit". Minor Planet Center. Retrieved 2014-05-09.
- Syuichi Nakano (2011-10-31). "209P/LINEAR (NK 2142)". OAA Computing and Minor Planet Sections. Retrieved 2012-10-03.
- "JPL Close-Approach Data: 209P/LINEAR" (last observation: 2014-05-26; arc: 10.48 years). Retrieved 2012-10-03.
- Gary W. Kronk. "209P/LINEAR". Cometography. Archived from the original on 2014-05-03. Retrieved 2014-05-03.
- "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)
- "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.
- Arecibo Radar [@AreciboRadar] (23 May 2014). "We saw comet 209P/LINEAR with radar! Looks like a narrow 2-kilometer bowling pin or peanut. Huzzah radar of comets!" (Tweet) – via Twitter.
- Alan Hale. "455. COMET 209P/LINEAR P/2008 X2". Earthrise Institute (Southwest Institute for Space Research). Retrieved 2012-10-03.
- Peter Jenniskens. "May Camelopardalids". SETI Institute. Retrieved 2014-05-25.
- "The next big meteor shower". IMCCE. Archived from the original on 2012-10-06. Retrieved 2012-10-03.
- "209P-ids 2014: prediction of activity". Archived from the original on 2014-04-14. Retrieved 2014-04-13.
- 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.
- "Camelopardalids meteor shower a bust, but not a surprise". The Washington Post. 2014-05-24. 10:07AM. Retrieved 2014-05-24.
- "Camelopardalids 2014: First Results". International Meteor Organization. Archived from the original on 2014-05-25. Retrieved 2014-05-25.
- "Meteor Activity Outlook for May 24-30, 2014". Archived from the original on 2014-05-25. Retrieved 2014-05-24.
- Orbital simulation from JPL (Java) / Horizons Ephemeris
- 209P/LINEAR – Seiichi Yoshida @ aerith.net
- Elements and Ephemeris for 209P/LINEAR – Minor Planet Center
- 209P/LINEAR at the Minor Planet Center's Database
- 209P/LINEAR – Kazuo Kinoshita (Dec. 21, 2008 )
- Camelopardalids 2014: First Results
- May Camelopardalids (SETI Institute / Peter Jenniskens)
- May Camelopardalids Fireball as seen from Pennsylvania via NASA Meteor Watch on Facebook
- How Scientists Chased a New Meteor Shower from the Sky (Space.com June 10, 2014)
- May Camelopardalids (MCM) May 24 2019 by CMOR radar