209P/LINEAR
{{Short description|Periodic comet}}
{{Infobox comet
| name=209P/LINEAR
| image= 209P 2014-05-28 NEOWISE image 3-color.png
| discoverer=LINEAR
1.0-m reflector
| discovery_date=3 February 2004 (asteroidal)
30 March 2004 (tail)
| designations=2004 CB
| epoch=2014-May-23
(JD 2456800.5)
| Earth_moid = {{Convert|0.05|AU|km|abbr=on}}
| semimajor=2.961 AU (a)
| perihelion=0.9695 AU (q)
| aphelion=4.952 AU (Q)
| eccentricity= 0.67258
| period=5.09 yr
| inclination=21.243°
| last_p=2019-Jun-12
2014-May-06
2009-Apr-15
| dimensions = 3.9 × 2.7 × 2.6 km
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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.
Observational history
The comet discovered on 3 February 2004 by Lincoln Near-Earth Asteroid Research (LINEAR) using a {{convert|1.0|m|in|adj=on}} 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.
209P/LINEAR came to perihelion (closest approach to the Sun) on 6 May 2014. On 29 May 2014 the comet passed {{convert|0.0554|AU|km mi|abbr=on|lk=on}} from Earth, but only brightened to about apparent magnitude 12. The 2014 Earth approach was the 9th closest known comet approach to Earth. 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. The radar imaging showed the comet nucleus is elongated and about 2.4 km by 3 km in size, later refined to 3.9 × 2.7 × 2.6 km. No evidence of large dust particles were detected in the coma.{{cite journal |last1=Howell |first1=Ellen S.|author1-link=Ellen Howell |last2=Nolan |first2=Michael C. |last3=Taylor |first3=Patrick A. |last4=Springmann |first4=Alessondra |last5=Rodriguez-Ford |first5=Linda |last6=Zambrano-Marin |first6=Luisa F. |last7=Benner |first7=Lance A. |last8=Brozovic |first8=Marina |last9=Giorgini |first9=Jon D. |last10=Hergenrother |first10=Carl |title=Radar images of Comet 209P/LINEAR: Constraints on shape and rotation |date=1 November 2014 |journal=AAS/Division for Planetary Sciences Meeting Abstracts |volume=46 |pages=209.24 |bibcode=2014DPS....4620924H |url=https://ui.adsabs.harvard.edu/abs/2014DPS....4620924H/abstract}} The comet also had very low water production, {{val|2.5|0.2|e=25}} mol/s, from an active area measuring just 0.007 km².
209P/LINEAR was recovered on 31 December 2018 at magnitude 19.2 by Hidetaka Sato.{{Cite web|url=http://www.aerith.net/comet/recovery.html|title=Comets Waiting for First Observation|website=www.aerith.net}}
Associated meteor showers
Preliminary results by Esko Lyytinen and Peter Jenniskens, later confirmed by other researchers, predicted 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. 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 {{convert|0.0002|AU|km mi|abbr=on|lk=on}} from Earth. The 2014 Camelopardalids only generated 10–15 visual meteors per hour.{{cite news|title=Camelopardalids meteor shower a bust, but not a surprise|url=https://www.washingtonpost.com/blogs/capital-weather-gang/wp/2014/05/24/camelopardalids-meteor-shower-a-bust-but-not-a-surprise/|access-date=2014-05-24|newspaper=The Washington Post|at=10:07AM|date=2014-05-24}} 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 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.{{Cite web |url=http://www.imo.net/node/1556 |title=Meteor Activity Outlook for May 24–30, 2014 |access-date=2014-05-24 |archive-url=https://web.archive.org/web/20140525233231/http://www.imo.net/node/1556 |archive-date=2014-05-25 |url-status=dead }}
The comet has also being suggested to be the parent body of the lambda Draconids, which is active from April 24 to June 4, and peaks around May 12. However it is possible that it is the same shower as the Camelopardalids.{{cite journal |last1=Šegon |first1=Damir |last2=Gural |first2=Peter |last3=Andreić |first3=Željko |last4=Skokić |first4=Ivica |last5=Korlević |first5=Korado |last6=Vida |first6=Denis |last7=Novoselnik |first7=Filip |title=New showers from parent body search across several video meteor databases |journal=WGN, Journal of the International Meteor Organization |date=1 April 2014 |volume=42 |pages=57–64 |url=https://articles.adsabs.harvard.edu/pdf/2014JIMO...42...57S |issn=1016-3115}}
209P/LINEAR may also be the source of the weak 6–14 June meteor shower "sigma Ursae Majorids" (SIM #677).
References
{{reflist
| refs =
|date=2004-03-31
|title=IAUC 8314: P/2004 CB; 2004ba, 2004bb
|publisher=IAU Central Bureau for Astronomical Telegrams
|url=http://www.cbat.eps.harvard.edu/iauc/08300/08314.html
|access-date=2012-10-03}}
|title=209P/LINEAR Orbit
|url=http://www.minorplanetcenter.net/db_search/show_object?object_id=209P
|publisher=Minor Planet Center
|access-date=2014-05-09}}
|date=2011-10-31
|title=209P/LINEAR (NK 2142)
|publisher=OAA Computing and Minor Planet Sections
|author=Syuichi Nakano
|author-link=Syuichi Nakano
|url=http://www.oaa.gr.jp/~oaacs/nk/nk2142.htm
|access-date=2012-10-03}}
|date=2008-12-12
|title=IAUC 9005: COMET P/2008 X4 = P/2003 K2 (CHRISTENSEN); 208P; V5580 Sgr
|publisher=IAU Central Bureau for Astronomical Telegrams
|url=http://www.cbat.eps.harvard.edu/iauc/09000/09005.html
|access-date=2012-10-03}} (password required)
|title = The next big meteor shower
|publisher = IMCCE
|url = http://www.imcce.fr/langues/en/ephemerides/phenomenes/meteor/DATABASE/209_LINEAR/2014/index.php
|access-date = 2012-10-03
|archive-url = https://web.archive.org/web/20121006013453/http://www.imcce.fr/langues/en/ephemerides/phenomenes/meteor/DATABASE/209_LINEAR/2014/index.php
|archive-date = 2012-10-06
|url-status = dead
}}
|title = 209P-ids 2014: prediction of activity
|url = http://feraj.narod.ru/Radiants/Predictions/209p-ids2014eng.html
|access-date = 2014-04-13
|archive-url = https://web.archive.org/web/20140414185802/http://feraj.narod.ru/Radiants/Predictions/209p-ids2014eng.html
|archive-date = 2014-04-14
|url-status = dead
}}
|last=Wiegert |first=Paul A. |author-link=Paul Wiegert
|author2=Quanzhi Ye
|title=Will Comet 209P/LINEAR Generate the Next Meteor Storm?
|journal=Monthly Notices of the Royal Astronomical Society |date=2013
|volume=437 |issue=4 |pages=3283–3287 |arxiv=1311.0235
|bibcode = 2014MNRAS.437.3283Y |doi = 10.1093/mnras/stt2127 |doi-access=free }}
|type=last observation: 2014-05-26; arc: 10.48 years
|title=JPL Close-Approach Data: 209P/LINEAR
|url=http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=209P;cad=1#cad
|access-date=2012-10-03}}
|title=455. COMET 209P/LINEAR P/2008 X2
|publisher=Earthrise Institute (Southwest Institute for Space Research)
|author=Alan Hale
|author-link=Alan Hale (astronomer)
|url=http://www.earthriseinstitute.org/coms45.html#455
|access-date=2012-10-03}}
|title = 209P/LINEAR
|work = Cometography
|author = Gary W. Kronk
|author-link = Gary W. Kronk
|url = http://cometography.com/pcomets/209p.html
|access-date = 2014-05-03
|archive-url = https://web.archive.org/web/20140503132812/http://cometography.com/pcomets/209p.html
|archive-date = 2014-05-03
|url-status = dead
}}
|last1=Schleicher
|first1=David G.
|last2=knight
|first2=Matthew m.
|title=The Extremely Low Activity Comet 209P/Linear During ITS Extraordinary Close Approach in 2014
|journal=The Astronomical Journal
|date=27 September 2016
|volume=152
|issue=4
|pages=89
|doi=10.3847/0004-6256/152/4/89
|arxiv=1605.01705
|doi-access=free
|bibcode=2016AJ....152...89S
}}
|title = Camelopardalids 2014: First Results
|publisher = International Meteor Organization
|url = http://www.imo.net/camelopardalids2014-results
|archive-url = https://web.archive.org/web/20140525200210/http://www.imo.net/camelopardalids2014-results
|url-status = dead
|archive-date = 2014-05-25
|access-date = 2014-05-25
}}
|title=May Camelopardalids
|publisher=SETI Institute
|author=Peter Jenniskens
|author-link=Peter Jenniskens
|url=http://meteor.seti.org/
|access-date=2014-05-25}}
{{cite web
|date=2014-05-29
|title=Arecibo Observatory Sees Comet 209P/LINEAR
|publisher=Universities Space Research Association (USRA)
|url=http://www.usra.edu/news/pr/2014/comet209PLINEAR/
|access-date=2014-05-29
|archive-url=https://web.archive.org/web/20140529224633/http://www.usra.edu/news/pr/2014/comet209PLINEAR/
|archive-date=2014-05-29
|url-status=dead
}}
|title=Horizons Batch for 209P/LINEAR on 2024-Jul-14
|publisher=JPL Horizons
|type=Perihelion occurs when rdot flips from negative to positive
|url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%27209P%27&START_TIME=%272024-Jul-13%27&STOP_TIME=%272024-Jul-16%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27
|accessdate=2023-07-06}} (JPL#141/Soln.date: 2023-Feb-13)
}}
External links
- {{JPL Small Body|id=1000487}}
- [http://www.aerith.net/comet/catalog/0209P/index.html 209P/LINEAR] – Seiichi Yoshida @ aerith.net
- [https://web.archive.org/web/20140626173246/http://scully.cfa.harvard.edu/cgi-bin/returnprepeph.cgi?d=c&o=0209P Elements and Ephemeris for 209P/LINEAR] – Minor Planet Center
- [http://www.minorplanetcenter.net/db_search/show_object?object_id=209P&commit=Show 209P/LINEAR] at the Minor Planet Center's Database
- [http://jcometobs.web.fc2.com/pcmtn/0209p.htm 209P/LINEAR] – Kazuo Kinoshita (Dec. 21, 2008 )
- [https://web.archive.org/web/20140525200210/http://www.imo.net/camelopardalids2014-results Camelopardalids 2014: First Results]
- [http://meteor.seti.org/ May Camelopardalids] (SETI Institute / Peter Jenniskens)
- [https://www.facebook.com/photo.php?v=714110968648132 May Camelopardalids Fireball as seen from Pennsylvania] via NASA Meteor Watch on Facebook
- [http://www.space.com/26199-meteor-shower-airplane-observations.html How Scientists Chased a New Meteor Shower from the Sky] (Space.com June 10, 2014)
- [https://twitter.com/pgbrown/status/1132033741801611264 May Camelopardalids (MCM) May 24 2019] by CMOR radar
- [https://www.meteornews.net/2022/06/07/meteor-activity-related-to-209p-linear-by-worldwide-radio-meteor-observations/ Meteor activity related to 209P/LINEAR by worldwide radio meteor observations] (2022)
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