Editing 55P/Tempel–Tuttle

{{Short description|Periodic comet}}
{{use dmy dates |date=October 2020}}
{{Infobox comet
| name =55P/Tempel–Tuttle
| image = Drawing of comet 55P by Tempel-from his personal notebooks in the Arcetri.jpg
| caption = Sketch of the comet by Wilhem Tempel, 19 December 1865
| discoverer =[[Wilhelm Tempel]] and [[Horace Parnell Tuttle]]
| discovery_date = 19 December 1865
| mpc_name     = P/1366 U1, P/1699 U1<br>P/1865 Y1, P/1965 M2<br>P/1997 E1
| designations = 1699 II; 1866 I;<br /> 1965 IV; 1965i
| orbit_ref    = {{r|jpldata}}
| epoch = 2031-05-14<br/>([[Julian date|JD]] 2463000.5)
| Earth_moid = {{Convert|0.008|AU|km|abbr=on}}
| semimajor = 10.46 [[Astronomical Unit|AU]]
| perihelion = 0.9644 AU
| aphelion = 19.96 AU
| eccentricity = 0.9078
| period = 33.83 [[Julian year (astronomy)|yr]]
| inclination = 162.57°
| last_p = 28 February 1998<ref name="Kinoshita"/>
| next_p = 20 May 2031<ref name="Yoshida-55p"/><ref name="Horizons2031"/><ref name="Kinoshita"/><ref name=MPC/>
| physical_ref = 
| M1 = 10{{r|jpldata}}
| dimensions   = {{cvt|3.6|km|mi}}{{r|jpldata}}
| rotation     = 14.79 or 15.31 hr{{r|IAUC_6816}}
}}

'''55P/Tempel–Tuttle''' (commonly known as '''Comet Tempel–Tuttle''') is a [[Retrograde and prograde motion|retrograde]] [[List of periodic comets|periodic]] [[comet]] with an [[orbital period]] of 33 years. It fits the classical definition of a Halley-type comet with a [[orbital period|period]] of between 20 and 200 years. It was independently discovered by [[Wilhelm Tempel]] on 19 December 1865, and by [[Horace Parnell Tuttle]] on 6 January 1866. It is the parent body of the [[Leonids|Leonid]] [[meteor shower]].

==Characteristics==
The nucleus of the comet was observed by [[Hubble Space Telescope]] during the 1998 apparition, and assuming an [[albedo]] of 0.04, its nucleus was estimated to have a mean radius of 1.8 km.{{r|IAUC_6851}} The nucleus has a reddish color, with a B−V 0.75 ± 0.05 and V−R 0.51 ± 0.05.<ref>{{cite journal |last1=Lamy |first1=P. |last2=Toth |first2=I. |title=The colors of cometary nuclei—Comparison with other primitive bodies of the Solar System and implications for their origin |journal=Icarus |date=June 2009 |volume=201 |issue=2 |pages=674–713 |doi=10.1016/j.icarus.2009.01.030}}</ref> A jet was observed emanating from the nucleus and based on its movement the rotation period was calculated to be 15.31 ± 0.03 and 14.79 ± 0.02 hours.{{r|IAUC_6816}} 

The spectrum of the comet revealed the presence of [[diatomic carbon]], NH2 and [Oi]. The relative production rates indicate that the comet is depleted in diatomic carbon when compared with Halley's comet. The gas-to-dust ratio also indicated it was gas rich compared with Halley's comet.<ref>{{cite journal |last1=Hamane |first1=T. |last2=Kawakita |first2=H. |last3=Suzuki |first3=B. |last4=Yano |first4=H. |last5=Yoshida |first5=Michitoshi |last6=Watanabe |first6=J. |title=Gas-to-dust ratio and chemical composition in comet 55P / Tempel–Tuttle |journal=The Institute of Space and Astronautical Science report. S.P |date=1 March 2003 |pages=17–22 |url=https://jaxa.repo.nii.ac.jp/?action=repository_action_common_download&item_id=36698&item_no=1&attribute_id=31&file_no=1}}</ref> The [[infrared]] [[spectrum]] of the comet closely resembled that of a [[black body]] with a temperature of 330 K and lacked [[silicate]] emission that has been detected in other comets.<ref>{{cite journal |last1=Lynch |first1=D |title=3- to 14- μm Spectroscopy of Comet 55P/Tempel–Tuttle, Parent Body of the Leonid Meteors |journal=Icarus |date=March 2000 |volume=144 |issue=1 |pages=187–190 |doi=10.1006/icar.1999.6260}}</ref>

[[William Huggins]] observed the spectrum of the comet in January 1866, making it the second time spectrographic observations of a comet were obtained.<ref>{{cite journal |last= Huggins |first = William |title=II. On the spectrum of comet 1, 1866 |journal=Proceedings of the Royal Society of London |date=31 December 1867 |volume=15 |pages=5–7 |doi=10.1098/rspl.1866.0004}}</ref>

==Sightings==
In 1699, it was observed by [[Gottfried Kirch]]<ref name="Kronk">[http://cometography.com/pcomets/055p.html C&MS: 55P/Tempel–Tuttle]</ref> but was not recognized as a [[periodic comet]] until the discoveries by Tempel and Tuttle during the 1866 [[perihelion]]. In 1933, S. Kanda deduced that the comet of 1366 was Tempel–Tuttle, which was confirmed by Joachim Schubart in 1965.<ref name="Kronk"/><ref>{{cite journal |last1=Schubart |first1=Joachim |title=Comet Tempel–Tuttle: Recovery of the Long-Lost Comet of the November Meteors |journal=Science |date=27 May 1966 |volume=152 |issue=3726 |pages=1236–1237 |doi=10.1126/science.152.3726.1236 |url=https://www.science.org/doi/abs/10.1126/science.152.3726.1236|url-access=subscription }}</ref> On 26 October 1366, the comet passed {{convert|0.0229|AU|km mi LD|abbr=on|lk=on}} from Earth.<ref name="closest"/> It is possible the comet was also observed in October 1234, however it is only mentioned briefly by a single Japanese source, and also a comet observed in China in January 1035 could be comet Temple–Tuttle, however unless it had undergone a major outburst, it would have been too dim to observe with the naked eye.<ref>{{cite journal |last1=Yeomans |first1=Donald K. |last2=Yau |first2=Kevin K. |last3=Weissman |first3=Paul R. |title=The Impending Appearance of Comet Tempel–Tuttle and the Leonid Meteors |journal=Icarus |date=December 1996 |volume=124 |issue=2 |pages=407–413 |doi=10.1006/icar.1996.0218}}</ref>

Comet Tempel–Tuttle was recovered by J. Schubart in images taken by Michiel John Bester on 30 June 1965 using the 10-inch telescope of [[Boyden Observatory]], South Africa. At that time the comet had an apparent magnitude of 16.<ref>{{cite journal |last1=Gingerich |first1= Owen |title=Periodic Comet Tempel–Tuttle (1965i) |journal=International Astronomical Union Circulars |date=4 October 1965 |volume=1926 |page=2 |url=http://www.cbat.eps.harvard.edu/iauc/01900/01926.html}}</ref> The presence of the comet was confirmed in plates obtained by [[Palomar Observatory]] on 30 June. These were the only two observations of the comet during the 1965 apparition.<ref>{{cite journal |last1=Gingerich |first1= Owen |title=Periodic Comet Tempel–Tuttle (1965i) |journal=International Astronomical Union Circulars |date=1 November 1966 |volume=1979 |page=1 |url=http://www.cbat.eps.harvard.edu/iauc/01900/01979.html}}</ref>

The comet was recovered on 4 March 1997 by Karen Meech, Olivier Hainaut and [[James "Gerbs" Bauer]], at the University of Hawai`i. At the time it was very faint (22.5 mag), but the recovery proved that it was returning on schedule and that its orbit was very well determined.<ref>{{cite web | url=https://www.astro.umd.edu/~farnham/tt/tthist.html | title=Comet 55P/Tempel–Tuttle Through History }}</ref> During the 1998 apparition the comet brightened more than predicted and reached an apparent magnitude of 7.4–7.8 in late February and could be observed with binoculars. It was last observed on 5 July 1998.<ref name="Kronk"/>

==Orbit==
The retrograde orbit of 55P/Tempel–Tuttle causes meteors to impact Earth at a high speed of 70&nbsp;km/s. The orbit intersects that of [[Earth]] nearly exactly, hence streams of material ejected from the comet during perihelion passages do not have to spread out much over time to encounter Earth. The comet currently has an Earth-[[Minimum orbit intersection distance|MOID]] of {{convert|0.008|AU|km mi|abbr=on|lk=on}}.<ref name=jpldata/> This coincidence means that past streams from the comet at perihelion are still dense when they encounter Earth, resulting in the 33-year cycle of Leonid meteor storms. For example, the 1833 meteor storm was created by the previous 1800 perihelion passage.<ref>[https://web.archive.org/web/20061206225925/http://www.arm.ac.uk/leonid/dust1833.html Archive of Leonid dust trail positions in 1833]</ref> Between 2021–2030, Earth will often pass through the meteoroid stream left behind from the 1733 orbit.<ref name="FuturePredictions2021-2030">{{cite web|last1=Mikhail|first1=Maslov|title=Leonids 2021–2030|url=http://feraj.ru/Radiants/Predictions/1901-2100eng/Leo2021-2030eng.html|url-status=live|access-date=10 June 2021|archive-date=10 June 2021|archive-url=https://web.archive.org/web/20210610102748/http://feraj.ru/Radiants/Predictions/1901-2100eng/Leo2021-2030eng.html}}</ref>

{| class="wikitable sortable" style="font-size: 0.9em;"
|+55P/Tempel–Tuttle Earth approaches
! Year
! [[Curve fitting|Nominal]] geocentric<br />distance ([[astronomical unit|AU]])
|-
|1366 ||{{Convert|0.023|AU|e6km|abbr=unit|lk=on}}<ref name="closest"/><ref name="Kronk"/>
|-
|1699 ||{{Convert|0.064|AU|e6km|abbr=unit}}<ref name="Kinoshita"/><ref name="Kronk"/>
|-
|1832 ||{{Convert|0.171|AU|e6km|abbr=unit}}<ref name="Earth1832"/><ref name="Kinoshita"/>
|-
|1998 ||{{Convert|0.356|AU|e6km|abbr=unit}}<ref name="Earth1998"/><ref name="Kinoshita"/>
|-
|2031 ||{{Convert|0.791|AU|e6km|abbr=unit}}<ref name="Earth2031"/><ref name="Kinoshita"/>
|-
|2163 ||{{Convert|0.132|AU|e6km|abbr=unit}}<ref name=jpldata/>
|}

55P/Tempel–Tuttle is estimated to have a [[Comet nucleus|nucleus]] of mass 1.2{{e|13}} kg<ref name=Jewitt>{{cite web |title=From Cradle To Grave: The Rise and Demise of the Comets |work=Comets II |author=David C. Jewitt |url=http://www2.ess.ucla.edu/~jewitt/papers/2005/J2005b.pdf |access-date=2009-11-12}}</ref> and radius 1.8&nbsp;km<ref name=Jewitt /> and a stream of mass 5{{e|12}} kg.<ref name=Jewitt />

{{multiple image
| align = left
| direction = horizontal
| width = 300
| header = Animation of 55P/Tempel–Tuttle{{'}}s orbit from 1990 to 2180
| image1 = Animation of 55P／Tempel–Tuttle orbit around Sun.gif
| caption1 = Around Sun
| image2 = Animation of 55P／Tempel–Tuttle orbit around Earth.gif
| caption2 = Around Earth
| footer ={{legend2| yellow| Sun}}{{·}}{{legend2| RoyalBlue| Earth}}{{·}}{{legend2| Cyan| Mars}}{{·}}{{legend2| Gold| Jupiter}}{{·}}{{legend2| Magenta|55P/Tempel–Tuttle }}
}}
{{clear}}

==See also==
*[[Comet IRAS–Araki–Alcock]] (Comet close approach 1983)
*[[Lexell's Comet]] (Lost comet close approach in 1770)
*[[252P/LINEAR]] (Close approach 2016)
*[[P/2016 BA14]] (Close approach 2016)

== References ==
{{reflist|refs=

<ref name="IAUC_6816">{{cite journal |last1=Jorda |first1=L. |last2=Lecacheux |first2=J. |last3=Colas |first3=F. |last4=Frappa |first4=E. |last5=Laques |first5=P. |last6=Keen |first6=R. |last7=Lehky |first7=M. |last8=Bortle |first8=J. |last9=O'Meara |first9=S. J. |last10=Kronk |first10=G. W. |title=Comet 55P/Tempel–Tuttle |journal=International Astronomical Union Circular |date=1 January 1998 |volume=6816 |pages=2 |url=http://www.cbat.eps.harvard.edu/iauc/06800/06816.html#Item2 |issn=0081-0304}}</ref> 

<ref name="IAUC_6851">{{cite journal |last1=Lamy |first1=P. |last2=Znojil |first2=V. |last3=Biver |first3=N. |title=Comet 55P/Tempel–Tuttle |journal=International Astronomical Union Circular |date=1 March 1998 |volume=6851 |pages=2 |url=http://www.cbat.eps.harvard.edu/iauc/06800/06851.html#Item2 |issn=0081-0304}}</ref>

<ref name="Yoshida-55p">{{cite web
  |date=2005-12-12
  |title=55P/Tempel–Tuttle
  |publisher=Seiichi Yoshida's Comet Catalog
  |author=Seiichi Yoshida
  |url=http://www.aerith.net/comet/catalog/0055P/index.html
  |access-date=2012-02-18}}</ref>

<ref name="Kinoshita">{{cite web
  |title=55P/Tempel–Tuttle past, present and future orbital elements
  |url=http://jcometobs.web.fc2.com/pcmtn/0055p.htm
  |work=Comet Orbit
  |first=Kazuo |last=Kinoshita
  |date=1999-09-16
  |archive-url=https://web.archive.org/web/20110520033054/http://jcometobs.web.fc2.com/pcmtn/0055p.htm
  |archive-date=2011-05-20
  |url-status=live
  |access-date=2023-09-06}}</ref>

<ref name=MPC>{{cite web
  |title=55P/Tempel–Tuttle Orbit
  |url=http://www.minorplanetcenter.net/db_search/show_object?object_id=55P
  |publisher=[[Minor Planet Center]]
  |access-date=2014-06-16}}</ref>

<ref name=jpldata>{{cite web
  |type=last observation: 1998-07-05
  |title=JPL Small-Body Database Browser: 55P/Tempel–Tuttle
  |publisher=[[Jet Propulsion Laboratory]]
  |url=https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=55P&view=OPC
  |archive-url=https://web.archive.org/web/20170202025456/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=55P;cad=1
  |archive-date=2017-02-02
  |url-status=live}}</ref>

<ref name="closest">{{cite web
  |title=Closest Approaches to the Earth by Comets
  |publisher=Minor Planet Center
  |url=http://www.minorplanetcenter.org/iau/lists/ClosestComets.html
  |access-date=2012-06-28}}</ref>

<ref name="Earth1832">{{cite web
  |title=Horizons Batch for 55P/Tempel–Tuttle (90000621) at 1832-Dec-16
  |publisher=[[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |type=J985 fits data all the way back to 1865
  |url=https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D55P%3BCAP%27&START_TIME=%271832-Dec-01%27&STOP_TIME=%271832-Dec-31%27&STEP_SIZE=%2760%27&QUANTITIES=%2719,20,23%27
  |accessdate=2023-09-06}}</ref>

<ref name="Earth1998">{{cite web
  |title=Horizons Batch for 55P/Tempel–Tuttle (90000621) at 1998-Jan-17
  |publisher=[[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |type=Closest Earth approach occurs when deldot flips from negative to positive
  |url=https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D55P%3BCAP%27&START_TIME=%271998-Jan-15%27&STOP_TIME=%271998-Jan-19%27&STEP_SIZE=%2730%27&QUANTITIES=%2719,20,23%27
  |accessdate=2023-09-06}}</ref>

<ref name="Earth2031">{{cite web
  |title=Horizons Batch for 55P/Tempel–Tuttle (90000621) at 2031-Feb-25
  |publisher=[[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |type=Closest Earth approach occurs when deldot flips from negative to positive
  |url=https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D55P%3BCAP%27&START_TIME=%272031-Feb-22%27&STOP_TIME=%272031-Feb-28%27&STEP_SIZE=%2730%27&QUANTITIES=%2719,20,23%27
  |accessdate=2023-09-05}} (JPL#J985/69 Soln.date: 2002-Jan-03)</ref>

<ref name="Horizons2031">{{cite web
  |title=Horizons Batch for 55P/Tempel–Tuttle (90000621) at 2031-May-20 23:45:52
  |publisher=[[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |type=Perihelion occurs when rdot flips from negative to positive
  |url=https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D55P%3BCAP%27&START_TIME=%272031-May-20%2023:40%27&STOP_TIME=%272031-May-20%2023:50%27&STEP_SIZE=%2730%27&QUANTITIES=%2719%27
  |accessdate=2023-08-26}} (JPL#J985/69 Soln.date: 2002-Jan-03)</ref>

}}

== External links ==
* [http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=55P;orb=1 Orbital simulation] from JPL (Java) / [http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=55P Horizons Ephemeris]
* [http://cometography.com/pcomets/055p.html Gary W. Kronk's Cometography]

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[[Category:Periodic comets]]
[[Category:Halley-type comets|055P]]
[[Category:Numbered comets|0055]]
[[Category:Near-Earth comets|055P]]
[[Category:Meteor shower progenitors|055P]]
[[Category:Astronomical objects discovered in 1865|18650119]]
[[Category:Discoveries by Wilhelm Tempel]]
[[Category:Discoveries by Horace Tuttle]]