Wikipedia

252P/LINEAR

Comet 252P/LINEAR is a periodic comet and near-Earth object discovered by the LINEAR survey on April 7, 2000. The comet is a Jupiter family comet, meaning that it passes quite close to the orbit of Jupiter.[4]

252P/LINEAR
Sequence of images shows Comet 252P/LINEAR near Earth.[1]
Discovery
Discovered byLincoln Near-Earth Asteroid Research (LINEAR)
Discovery date2000/04/07
Orbital characteristics
Epoch2015-Aug-01 (JD 2457235.5)
Observation arc16 years
Aphelion5.1079 AU
Perihelion0.9961 AU
Semi-major axis3.0520 AU
Eccentricity0.6736
Orbital period5.33 years (1947 days)
Inclination10.4046°
Last perihelion2021/07/11[2]
2016/03/15
2010/11/13
Next perihelion2026-Nov-07[3]
TJupiter2.8
Earth MOID0.0138 AU (2,060,000 km)
Jupiter MOID0.1973 AU (29,520,000 km)[4]
Physical characteristics
Dimensions100-400 meters
Comet total
magnitude (M1)		18.9 ± 1
Comet nuclear
magnitude (M2)		22.7 ± 0.9

At some point, 252P/LINEAR separated from a second object designated P/2016 BA14 (PANSTARRS), that was discovered in January 2016.[5][6] The nucleus of P/2016 BA14 is 1,000 meters wide, which is larger than the nucleus of 252P, which is estimated to be 600 meters across, but it is less active.[7] 252P/LINEAR approached as close as 0.0356 AU (13.9 LD) to Earth on 21 March 2016.[8]

Observational history

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The comet was discovered on 7 April 2000 by the Lincoln Near-Earth Asteroid Research with a 1.0 m f/2.15 reflector telescope as a fast moving object. Lisa Brown-Manguso noticed that it had a diffuse tail, indicating it is a comet. Upon discovery the comet had a magnitude of 17–18.[9] After additional observations a short period orbit was calculated, indicating that the comet had an orbital of 5.4 years and perihelion at 1.00293 AU.[10] During the 2000 apparition the comet approached to 0.10 AU from Earth.[11] The comet was recovered on 9 June 2011 by Spacewatch Project at Kitt Peak Observatory, Arizona. Its apparent magnitude was estimated to be 22.7.[12][13]

The 2016 apparition was very favorable, as the comet passed 0.0356 AU (0.00533 billion km) from Earth on 21 March 2016. That is the fifth closest comet approach to Earth.[14] The comet during that apparition was more active than predicted, reached an apparent magnitude of 4.5 and became dimmly visible by naked eye.[15] It was observed by Hubble Space Telescope on 4 April 2016, and thus became the closest celestial object Hubble has observed, other than the Moon. The images revealed a narrow, well-defined jet of dust ejected by the icy comet nucleus.[16]

 
The comet during the 2016 apparition above an auxiliary telescope of ESO's Very Large Telescope.

During the 2021 apparition the comet was again brighter than expected. On August 8 the visual magnitude of the comet was estimated to be about 10.5, while on 10 August the magnitude was estimated to be 13.1 based on CCD photometry and the coma was measuring 3.6 arcminutes across, while no tail was detected.[17]

Orbit

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The comet is an Earth-Jupiter family comet, meaning that it passes quite close to both Earth and Jupiter.[4] This causes its orbit to be perturbed frequently on an astronomical timescale. The inclination is 10.4°, the orbital period 5.33 years for epoch July 2021 and its perihelion is at 1.0005 AU. For epoch November 2026 the perihelion will be 1.0037 AU.[17]

The nominal orbit of 252P/LINEAR [2001] (K102/1) was thrown into the near-Earth region by Jupiter in 1800s, and probably this is the first time the comet is so close to the Sun.[11] Since its Jupiter MOID is currently 0.2 AU,[4] Jupiter remains the primary factor in its orbital disruption. The comet will approach Jupiter at 0.76 AU on 22 December 2033 and at 0.11 AU on 3 August 2046.[17]

The comet passed at a distance of 0.0356 AU on 21.6 March 2016 and another close flyby from Earth will take place on 18 March 2032, at a distance of 0.050 AU.[17]

Physical characteristics

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During the close flyby of 2016 the comet was observed by Hubble Space Telescope. The images revealed a narrow sunward jet from the nucleus. The jet changed positions indicating a rotation of the comet every 7.24 ± 0.07 hours. The light curve of the nucleus however indicated a period of 5.41 ± 0.07 hours.[7] Observations from Lowell Observatory showed that the CN features of the coma indicated a period of around 22 hour or a sub-multiple and other features were repeated every ~95.5 hr, implying an actual period of 7.35 ± 0.05 hours.[18] It is possible that the comet is non principal axis rotator.[7] The nucleus was estimated to have an radius of 0.3 ± 0.03 km.[7]

The near infrared spectrum of the comet revealed the presence of H2O, CH3OH, C2H6, and HCN. The comet had a typical composition for a Jupiter family comet, but the abundance of methanol and ethane was higher and formaldehyde production was lower than that of other short period comets. The average production rate was (4.9±0.1)×1027 moles/s in April 2016.[19] The CN production between 27 March and 3 April was 6.4×1024 mol/s. The dust production at the same time was 4 kg/s, indicating the a dust to gas mass ration of 0.025, which is among the lowest observed values for a comet.[20]

Associated meteor shower

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252P/LINEAR is predicted to perhaps make a weak new meteor shower during its 2016 approach. Peter Jenniskens and Jeremie Vaubaillon calculated that possible meteors from this comet would radiate from the constellation of Lepus, south of Orion, from a radiant at R.A. = 77.0 deg, Decl. = -16.3 deg., with a slow geocentric velocity of Vg = 11.1 km/s on March 28 and 29, when Earth reaches the comet orbit. Rates will be low. There are no encounters with the dust trails created since A.D. 1850, but instead a diffuse cloud of perturbed meteoroids ejected during 1894-1926 is calculated to be in Earth's path (see CBET telegram 4267).[21]

Quan-Zhi Ye calculated that possible meteors from comet P/2016 BA14 (PANSTARRS) would radiate from the constellation Columba, south of Lepus during the late UT hours of March 20. The radiant is at R.A. = 82 deg, Decl. = -39 deg, with geocentric velocity Vg = 14.1 km/s. Meteoroids ejected since A.D. 1750 were studied, with also no dust trail encounters found in 2016 (see CBET telegram 4259).[22]

A meteor shower has been observed with a similar orbit to 252P/LINEAR, previously known as the March Lyncids, in the constellation Lynx.[citation needed] It is not known for certain if the shower is related to the comet.

Fragment

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Main article: P/2016 BA14
 
252P/LINEAR and 2016 BA14 images during their closest approaches in March 2016

P/2016 BA14 was radar imaged at distance of 2.2 million miles (9 lunar distances) during a flyby of Earth in 2016, one day after the closest flyby of 252P/LINEAR.[23] This enabled the size of the nucleus to be calculated to be about 3000 to 3300 feet (1 km) in diameter, which was bigger than expected.[23]

When 2016 BA14 was discovered in January 2016 by a PanSTARRS telescope, it was thought to be an asteroid and went by a provisional minor planet designation 2016 BA14.[24] An astronomer then realized the body's orbit was very similar to 252P/LINEAR, which lead to a follow-up observation by the Lowell Discovery Telescope.[24] The body showed a tail, identifying it as a probable comet and then named P/2016 BA14.[24] After being reobserved in 2020 it was numbered and is now known as 460P/PanSTARRS.[25]

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Comet 252P/LINEAR appearing as a fuzzy and greenish blob above Paranal Observatory[26]

See also

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References

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  1. ^ "Comet 252P/LINEAR". Retrieved 16 May 2016.
  2. ^ "252P/LINEAR Orbit". Minor Planet Center. Retrieved 2017-04-09.
  3. ^ "Horizons Batch for 252P/LINEAR (90001202) on 2026-Nov-07 (Not valid before 2016-04-01)" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 2021-09-17. (JPL K212/2/Soln.date: 2021-Sep-07)
  4. ^ a b c d "JPL Small-Body Database Browser: 252P/LINEAR (Not valid before 2016-04-01)" (last observation: 2016-07-31; arc: 117 days).
  5. ^ JPL SBDB: 2016BA14
  6. ^ Agle, DC; Brown, Dwayne; Cantillo, Laurie (18 March 2016). "A 'Tail' of Two Comets". NASA. Retrieved 18 March 2016.
  7. ^ a b c d Li, Jian-Yang; Kelley, Michael S. P.; Samarasinha, Nalin H.; Farnocchia, Davide; Mutchler, Max J.; Ren, Yanqiong; Lu, Xiaoping; Tholen, David J.; Lister, Tim; Micheli, Marco (7 September 2017). "The Unusual Apparition of Comet 252P/2000 G1 (LINEAR) and Comparison with Comet P/2016 BA 14 (PanSTARRS)". The Astronomical Journal. 154 (4): 136. arXiv:1708.05190. doi:10.3847/1538-3881/aa86ae.
  8. ^ "NEO Earth Close Approaches". Archived from the original on March 7, 2014. Retrieved March 4, 2014.
  9. ^ Marsden, Brian G. (8 April 2000). "Comet P/2000 G1 (LINEAR)". International Astronomical Union Circular (7396): 5. ISSN 0081-0304.
  10. ^ Green, D. W. E (26 April 2000). "Comet P/2000 G1 (LINEAR)". International Astronomical Union Circular (7408): 5. ISSN 0081-0304.
  11. ^ a b Ye, Quan-Zhi; Brown, Peter G.; Wiegert, Paul A. (1 February 2016). "Comet 252P/LINEAR: Born (Almost) Dead?". The Astrophysical Journal. 818 (2): L29. arXiv:1601.07837. Bibcode:2016ApJ...818L..29Y. doi:10.3847/2041-8205/818/2/L29. ISSN 0004-637X.
  12. ^ Scotti, J. V.; Williams, G. V. (June 2011). "Comet P/2000 g1 = 2011 L5 (linear)". Minor Planet Electronic Circulars. 2011-L41. ISSN 1523-6714.
  13. ^ Scotti, J.; Williams, G. V. (1 June 2011). "Comet P/2011 L5 (LINEAR)". Central Bureau Electronic Telegrams. 2742: 1. Bibcode:2011CBET.2742....1S.
  14. ^ Well, Wall (23 March 2016). "Two Comets Just Made Historic Near-Earth Flybys: See Images and Video". Space.com. Retrieved 4 April 2023.
  15. ^ "ICQ/CBAT/MPC: Recent Comet Magnitudes". www.icq.eps.harvard.edu. Retrieved 4 April 2023.
  16. ^ "Comet 252P/LINEAR". www.spacetelescope.org. 13 May 2016. Retrieved 4 April 2023.
  17. ^ a b c d Green, Daniel (15 August 2021). "COMET 252P/LINEAR". Central Bureau for Astronomical Telegrams. 5018: 1.
  18. ^ Knight, Matthew M.; Schleicher, David G. (October 2016). "Observations of comet 252P/LINEAR during its historically close approach to Earth in 2016 from Lowell Observatory". AAS/Division for Planetary Sciences Meeting Abstracts #48. 48. Bibcode:2016DPS....4821702K.
  19. ^ Paganini, L.; Camarca, M. N.; Mumma, M. J.; Faggi, S.; Lippi, M.; Villanueva, G. L. (6 August 2019). "Observations of Jupiter Family Comet 252P/LINEAR During a Close Approach to Earth Reveal Large Abundances of Methanol and Ethane". The Astronomical Journal. 158 (3): 98. Bibcode:2019AJ....158...98P. doi:10.3847/1538-3881/ab289c. ISSN 1538-3881.
  20. ^ Coulson, Iain M.; Cordiner, Martin A.; Kuan, Yi-Jehng; Tseng, Wei-Ling; Chuang, Yo-Ling; Lin, Zhong-Yi; Milam, Stefanie N.; Charnley, Steven B.; Ip, Wing-Huen (1 April 2017). "JCMT Spectral and Continuum Imaging of Comet 252P/LINEAR". The Astronomical Journal. 153 (4): 169. Bibcode:2017AJ....153..169C. doi:10.3847/1538-3881/aa6440. ISSN 0004-6256.
  21. ^ "COMET 252P/LINEAR" (TXT). Cbat.eps.harvard.edu. Retrieved 2016-04-01.
  22. ^ "POSSIBLE METEOR ACTIVITY FROM COMET P/2016 BA14" (TXT). Cbat.eps.harvard.edu. Retrieved 2016-04-01.
  23. ^ a b "Flyby Comet Was WAY Bigger Than Thought". Space.com. Retrieved 2018-11-07.
  24. ^ a b c "Comet PanSTARRS 2016's Historic Flyby of Earth". 16 March 2016.
  25. ^ Green, Daniel (2 April 2023). "COMET P/2016 BA_14 = P/2020 U6 (PANSTARRS)". Central Bureau for Astronomical Telegrams. 5243. Retrieved 3 April 2023.
  26. ^ "An Infrequent Visitor to the Skies Above Paranal". Retrieved 7 April 2016.
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