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.[5] It was given the permanent number 209P on 12 December 2008 as it was the second observed appearance of the comet.[6] Prediscovery images of the comet, dating back to December 2003, were found during 2009.[5] Arecibo imaging in 2014 showed the comet nucleus is peanut shaped and about 2.4 km in diameter.[7][8] The comet has extremely low activity for its size and is probably in the process of evolving into an extinct comet.
Discovery | |
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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° |
Earth MOID | 0.05 AU (7,500,000 km)[3] |
Last perihelion | 2019-Jun-12[2] 2014-May-06[4] 2009-Apr-15[4] |
Next perihelion | 2024-Jul-14 |
209P/LINEAR was recovered on 31 December 2018 at magnitude 19.2 by Hidetaka Sato, but not officially announced yet.[9]
209P/LINEAR came to perihelion (closest approach to the Sun) on 6 May 2014.[4] On 29 May 2014 the comet passed 0.0554 AU (8,290,000 km; 5,150,000 mi) from Earth,[3] but only brightened to about apparent magnitude 12.[10] The 2014 Earth approach was the 9th closest known comet approach to Earth.[11]
Preliminary results by Esko Lyytinen and Peter Jenniskens, later confirmed by other researchers, predicted[12][13][14] 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.[12] All the trails from the comet from 1803 through 1924 were expected to intersect Earth's orbit during May 2014.[12] 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.[14] The 2014 Camelopardalids only generated 10–15 visual meteors per hour.[15][16] But the expected radiant and date of visual maximum were correctly predicted.[16] The shower peaked around 6h UT on 24 May 2014.[16] 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.[17]
209P/LINEAR may also be the source of the weak 6–14 June meteor shower "sigma Ursae Majorids" (SIM #677).[11]
Numbered comets | ||
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Previous 208P/McMillan |
209P/LINEAR | Next 210P/Christensen |