View source for 12P/Pons–Brooks

{{Short description|Periodic comet with 71-year orbit}}
{{use dmy dates |date=March 2024}}
{{Infobox comet
| name = {{nobr|12P/Pons–Brooks}}
| image = Pons brooks.jpg 
| caption = {{nobr|12P/Pons–Brooks}} photographed on 7&nbsp;March 2024
| discoverer = [[Jean-Louis Pons]]<br/>[[William Robert Brooks]]
| discovery_date = 12 July 1812
| designations = 1812; 1884&nbsp;I; 1954&nbsp;VII;<ref name=jpldata/> {{nobr|C/1457 A{{sub|1}} ;}} {{nobr|C/1385 U{{sub|1}} }}<ref name=Meyer2020/><ref>
{{cite report
 |first=Maik |last=Meyer
 |title=Comet {{nobr|12P/Pons–Brooks}} – identical to comets {{nobr|C/1457 A{{sub|1}} }} and {{nobr|C/1385 U{{sub|1}} }}
 |website=comethunter.de
 |url=http://www.comethunter.de/12P.pdf
}}
</ref>
| epoch = 2024-05-10<ref name=MPC/>
| semimajor = 17.199&nbsp;[[astronomical unit|AU]]
| perihelion = 0.78078&nbsp;[[astronomical unit|AU]]
| aphelion = 33.616&nbsp;[[astronomical unit|AU]]
| eccentricity = 0.95460
| period = 71.32 [[Julian year (astronomy)|jyr]]<br/>{{time interval|1954-05-22|2024-04-21|abbr=on}} {{small|(perihelion to perihelion)}}
| inclination = 74.191°
| asc_node= 255.86°
| arg_peri = 198.99°
| Earth_moid = {{convert|0.176|AU|e6km|abbr=unit}}
| last_p = 21&nbsp;April 2024<ref name=Horizons2024/>{{efn|name=Horizons}}<br>22&nbsp;May 1954<ref name=Yoshida/><ref name=MPC/> <br/>25&nbsp;January 1884 <br/>15&nbsp;September 1812
| next_p =  15 August 2095
| M1 = 5<ref name=jpldata/>
| dimensions = {{val|34|12|u=km}}<ref name=Quanzhi2020/>
| rotation = {{val|57|1|u=hr}}<ref>
{{cite journal
 |first1 = M.M. |last1 = Knight         |first2 = B.A. |last2 = Skiff
 |first3 = D.G. |last3 = Schleicher     |first4 = L.G. |last4 = Spiro
 |first5 = I.C. |last5 = Fernald        |first6 = B.Y. |last6 = Guan
 |first7 = L.J. |last7 = Lininger       |first8 = J.A. |last8 = Larsen
 |display-authors = 6
 |date = 6 March 2024
 |title = ATel #16508: Rotation period of comet {{nobr|12P/Pons–Brooks}} from CN coma morphology
 |journal = [[The Astronomer's Telegram]]
 |url=https://www.astronomerstelegram.org/?read=16508
 |access-date = 9 March 2024
}}
</ref>
}}

{{nobr|'''12P/Pons–Brooks'''}} is a [[List of periodic comets|periodic]] [[comet]] with an [[orbital period]] of 71&nbsp;years.<ref name="NYT-20240416">{{cite news |last=Miller |first=Katrina |title=Comet Pons–Brooks Is Having Its Last Hurrah – Soon, this devil-horned comet won't be visible for another seven decades. |url=https://www.nytimes.com/2024/04/16/science/comet-pons-brooks.html |date=16 April 2024 |work=[[The New York Times]] |url-status=live |archiveurl=https://archive.today/20240417062119/https://www.nytimes.com/2024/04/16/science/comet-pons-brooks.html |archivedate=17 April 2024 |accessdate=17 April 2024 }}</ref> Comets with an orbital period of 20–200&nbsp;years are referred to as [[Halley-type comet]]s. It is one of the brightest [[List of numbered comets|known periodic comets]], reaching an [[Absolute magnitude#Cometary magnitudes|absolute visual magnitude]] of about&nbsp;5 in its approach to perihelion.<ref name=Meyer2020/> Comet Pons–Brooks was conclusively discovered at [[Marseille Observatory|Marseilles Observatory]] in July 1812 by [[Jean-Louis Pons]], and on its next appearance in 1883 by [[William Robert Brooks]].<ref>{{Cite journal |title=The intermediate comets and nongravitational effects |last=Yeomans |first=D.K. |author-link=Donald K. Yeomans |date=April 1986 |journal=[[Astronomical Journal]] |volume=91 |issue=4 |pages=971–973 |issn=0004-6256 |bibcode=1986AJ.....91..971Y |doi=10.1086/114073}}</ref> However it has been confirmed {{nobr|12P/Pons–Brooks}} was observed before the 19th century.

The last [[perihelion]] passage was 21&nbsp;April 2024,<ref name=Horizons2024/>{{efn|name=Horizons}} with closest approach to Earth being {{convert|1.55|AU|e6km|abbr=unit|lk=on}} on 2&nbsp;June 2024.<ref name=Earth20240602/> During the 2024 apparition the comet brightened to a magnitude of 3.8.<ref>{{cite web |title=Brightest comets seen since 1935 |url=http://www.icq.eps.harvard.edu/brightest.html |website=www.icq.eps.harvard.edu |access-date=16 November 2024}}</ref> The [[comet nucleus]] is estimated to be around 30&nbsp;km in diameter, assuming it was not producing too much dust and gas during the 2020 [[Photometry (astronomy)|photometric measurements]].<ref name=Quanzhi2020/>

{{nobr|12P/Pons–Brooks}} is hypothesized to be the parent body of the weak December {{mvar|κ}}&nbsp;Draconids [[meteor shower]] that is active from about 29&nbsp;November to 13&nbsp;December.<ref name=Tomko2016/>

== Observational history ==
=== Before 1812 ===
Comet {{nobr|12P/Pons–Brooks}} has been identified as a comet observed in 1385 and in 1457. The 1385 apparition was very favourable and the comet was recorded by the Chinese in [[Ming Shilu]] and was also mentioned in some European sources. A comet observed by [[Paolo dal Pozzo Toscanelli]] in January&nbsp;1457 and mentioned in Chinese sources is also identified as comet {{nobr|12P/Pons–Brooks.}} In both apparitions the comet had magnitude&nbsp;3 or brighter, not accounting for possible outbursts. It is possible that it was also a comet recorded in Chinese sources in September 245 CE.<ref name=Meyer2020/>

So-Yeon Park & Jong-Chul Chae (2007)<ref name=Park-Chae-2007/> suggested that comet {{nobr|12P/Pons–Brooks}} was also the comets recorded in Asian sources in 1313 and 1668.<ref name=Park-Chae-2007>{{harvp|Park|Chae|2007}}</ref> However, Meyer ''et al.''<ref name=Meyer2020/> argue that in the 1313 apparition, the comet would have been difficult to observe, being dim and close to the Sun, while the suggested position in Gemini contradicts the calculated location of comet Pons–Brooks in Aries. The March&nbsp;1668 comet described by Koreans is probably the bright sungrazing comet observed by Europeans, whose orbit is no way compatible with that of comet {{nobr|12P/Pons–Brooks.}}<ref name=Meyer2020/>

=== 1812 discovery ===
[[File:Comet Pons-Brooks by H.C. Wilson on Jan 21, 22 1884.jpg|thumb|Sketches of comet {{nobr|12P/Pons–Brooks}} from 21–22&nbsp;January 1884]]
Comet {{nobr|12P/Pons–Brooks}} was discovered on 12&nbsp;July 1812, by [[Jean-Louis Pons]]. Independently, this comet was later found by Vincent Wisniewski on 1&nbsp;August, and [[Alexis Bouvard]] on 2&nbsp;August the same year. The comet was spotted with the naked eye on 13&nbsp;August and by the end of the month a tail measuring 2&nbsp;degrees in length was reported.<ref name=kronk/> Shortly after its initial discovery it was found to have an orbital period of about 70&nbsp;years with an error of about 5&nbsp;years. [[Johann Franz Encke]] determined a definitive orbit with a period of 70.68&nbsp;years. This orbit was used to generate an ephemeris for the 1883–1884 return.<ref name=kronk/>

=== 1884 ===
On 2&nbsp;September 1883 a (faint) comet was accidentally discovered by [[William Robert Brooks]] and later identified with the comet of 1812.<ref name=kronk/> An outburst was observed on 21–23&nbsp;September 1883, as the comet brightened from [[apparent magnitude|magnitude]]&nbsp;10–11 to 8–8.5, and its appearance changed from diffuse to star-like.<ref>
{{cite journal
 |last = Chandler |first = S.C. Jr.|author-link=Seth Carlo Chandler
 |date = 1 November 1883
 |title = On the outburst in the light of the comet Pons–Brooks Sept.&nbsp;21–23
 |journal = [[Astronomische Nachrichten]]
 |volume = 107  |issue = 9  |pages = 131–133
 |doi = 10.1002/asna.18841070902
 |issn = 0004-6337 |bibcode = 1883AN....107..131C
 |url = https://adsabs.harvard.edu/full/1883AN....107..131C
}}
</ref>
The comet became visible with naked eye in 20&nbsp;November and brightened up to magnitude&nbsp;3. The comet was reported to experience outbursts on 1&nbsp;January and 19&nbsp;January.<ref name=kronk/> This year it traveled from Scheat and Markab in western Pegasus, 13&nbsp;January 1884; southward (through Pisces) to reach perihelion below [[Iota Ceti|Iota]] and [[Beta Ceti]] (~[[right ascension|RA]]&nbsp;0h, [[declination|dec.]]&nbsp;−10°) around 24&nbsp;January.<ref>
{{cite journal
 | first = William | last = Dawson
 | year = 1884
 | title = The Pons–Brooks Comet
 | journal = The Friend
 | volume = 57  | page = 194
}}</ref> It was last seen in June&nbsp;1884.<ref name=kronk/>

=== 1954 ===
The comet was recovered on 20&nbsp;June 1953 when it was 4.5&nbsp;[[astronomical unit|AU]] from the Sun.<ref name=kronk/> The comet outburst from [[apparent magnitude|magnitude]]&nbsp;18 to magnitude&nbsp;13 on 1&nbsp;July 1953. Another outburst occurred in March 1954, the fourth observed in that apparition.<ref name=Porter1955/> On 23&nbsp;April the comet was estimated magnitude&nbsp;6.4, and its tail was half a degree long.<ref name=Porter1955/> Pons–Brooks came to [[Apsis#Perihelion and aphelion|perihelion]] on 22&nbsp;May 1954<ref name=Yoshida/> when it was {{nobr|1.7 AU}} from Earth. After perihelion it became better visible from the south hemisphere. It was last observed on 4&nbsp;September 1954 when it was {{nobr|1.9 AU}} from the Sun.<ref name=Porter1955>
{{cite journal
 |last = Porter  |first = J.G.
 |date = 1 April 1955
 |title = Comets (1954)
 |journal = [[Monthly Notices of the Royal Astronomical Society]]
 |volume = 115  |issue = 2  |pages = 190–198
 |doi = 10.1093/mnras/115.2.190 |doi-access = free
}}
</ref>
On 10&nbsp;December 1954, the [[Meteor shower#Origin of meteoroid streams|meteor stream]] of comet Pons–Brooks passed about {{convert|0.12|AU|e6km|abbr=unit}} from Earth, resulting in potential meteors impacting Earth's atmosphere at relative velocity 45&nbsp;km/s.<ref>
{{cite book
 |first1=G.A. |last1=Chebotarev
 |first2=E.I. |last2=Kazimirchak-Polonskaya
 |first3=B.G. |last3=Marsden
 |date=1972
 |title=The Motion, Evolution of Orbits, and Origin of Comets
 |publisher=D. Reidel Publishing Company
 |isbn=978-94-010-2875-2
 |page=[https://books.google.com/books?id=cdnsCAAAQBAJ&q=%221954%20VII%22&pg=PA473 473]
 |url=https://books.google.com/books?id=cdnsCAAAQBAJ&q=%221954%20VII%22&pg=PA473
 |access-date=6 July 2020
}}
</ref>

=== 2024 passage ===
[[File:12P 2023-07-27 J87.png|thumb|The comet on 27&nbsp;July 2023, a week after its first outburst.]]
On 10&nbsp;June 2020 Pons–Brooks was recovered at [[apparent magnitude]]&nbsp;23 by the [[Lowell Discovery Telescope]] when the comet was beyond the orbit of [[Saturn]] at {{convert|11.9|AU|e9km|abbr=unit|lk=on}} from the Sun,<ref name=MPEC2020-M114/><ref name=Quanzhi2020/> with the uncertainty in the comet's heliocentric distance being roughly {{nobr|± 10 000 km}} at the time. The comet underwent 14 well-documented outbursts, observed between June 13, 2023, and April 2024, at heliocentric distances ranging from 4.26 au to 0.85 au.<ref>{{cite journal |title=Mass of particles released by comet 12P/Pons-Brooks during 2023-2024 outbursts |journal=Monthly Notices of the Royal Astronomical Society |date=2025 |doi=10.1093/mnras/staf219|doi-access=free |last1=Gritsevich |first1=Maria |last2=Wesołowski |first2=Marcin |last3=Castro-Tirado |first3=Alberto J. |arxiv=2501.15958 }}</ref><ref name=CBET5280>
{{cite report
 |last = Green  |first = Daniel
 |date = 21 July 2023
 |title = Comet {{nobr|12P/Pons–Brooks}}
 |id = Electronic Telegram 5280
 |publisher=[[Central Bureau for Astronomical Telegrams]]
 |url=http://www.cbat.eps.harvard.edu/iau/cbet/005200/CBET005280.txt
 |access-date=22 July 2023
}}
</ref><ref>
{{cite news
 |title = {{nobr|12P/Pons–Brooks}} in outburst!
 |website = groups.io/g/comets-ml
 |url  = https://groups.io/g/comets-ml/message/31504
 |access-date = 2024-03-19
}}</ref>
After perihelion, two additional outbursts were observed in summer 2024, at heliocentric distances of 1.20 au and 2.26 au. 
The coma had expanded to a diameter of 600,000&nbsp;kilometers by 5&nbsp;August, having an expansion rate of 220&nbsp;m/s. Although initially spherical, the coma became asymmetrical due to the effects of [[radiation pressure]] on the dust.<ref>
{{cite journal
 |first1 = Federico |last1 = Manzini         |first2 = Virginio  |last2 = Oldani
 |first3 = Paolo    |last3 = Ochner          |first4 = Luigi R.  |last4 = Bedin
 |first5 = Andrea   |last5 = Reguitti
 |date=17 August 2023
 |title=Comet {{nobr|12P/Pons–Brooks}} outburst and coma expansion rate
 |issue=ATel #16194
 |journal=[[The Astronomer's Telegram]]
 |url=https://www.astronomerstelegram.org/?read=16194
}}
</ref>
The comet outburst again on 5&nbsp;October 2023 from magnitude&nbsp;15 to magnitude&nbsp;11 (brightening by ~40×).<ref name=ST20231006/> Two more outbursts were recorded on 1&nbsp;November and 14&nbsp;November, with the comet brightening to apparent magnitude&nbsp;9.3 after the later.<ref>
{{cite web
 |title = Thursday 16 November 2023
 |series = Spaceweather.com Time Machine
 |website = spaceweather.com
 |url = https://www.spaceweather.com/archive.php?day=16&month=11&year=2023&view=view
 |access-date = 17 November 2023
}}
</ref>
Outbursts were also observed on 14&nbsp;December<ref>
{{cite web
 |title = Cometas visibles en Enero de 2024
 |website = CometoGrafía
 |url = https://cometografia.es/cometas-visibles/#012P-2024
 |access-date = 20 January 2024  |lang=es
}}
</ref>
and 18&nbsp;January 2024.<ref>
{{cite web
 |title = Friday 19 January 2024
 |website = spaceweather.com
 |series = Spaceweather.com Time Machine
 |url = https://www.spaceweather.com/archive.php?view=1&day=19&month=01&year=2024
 |access-date = 20 January 2024
}}
</ref>

{| class="wikitable" style="text-align: center; font-size: 0.9em;"
|+Outbursts{{efn|name=Outburst}} during 2023
! Date
! Start<br/>[[Apparent magnitude|mag]]
! Outburst<br/>mag
! Brightening
! Sun distance<br/>([[astronomical unit|AU]])
! [[Elongation (astronomy)|Solar<br/>elongation]]
|-
| 2023-07-20<ref name=CBET5280/> || 16 || 11 || 100× || 3.9 || 101°
|-
| 2023-10-05<ref name=ST20231006/> || 15 || 11 || 40× || 3.1 || 80°
|}

By mid February the comet had brightened to magnitude&nbsp;7.5 and had developed an ion tail about two degrees long that featured jets and filaments.<ref>
{{cite AV media
 |last = Chambo  |first = Pepe
 |title = The iconic tail of comet {{nobr|12P/Pons–Brooks}}
 |magazine = Sky and Telescope
 |department = online gallery
 |medium = astrophoto
 |date = 15 February 2024
 |access-date = 17 February 2024
 |url = https://skyandtelescope.org/online-gallery/the-ionic-tail-of-comet-12p-pons-brooks/
}}
</ref>
A minor outburst took place on 29&nbsp;February, with the comet brightening by 0.9&nbsp;magnitudes.<ref name=CBET5369/><ref>
{{cite news
 |last = James |first = Nick
 |date = 1 March 2024
 |title = {{nobr|12P/Pons–Brooks}} small outburst 2024 Feb&nbsp;29
 |publisher = [[British Astronomical Association]]
 |website = britastro.org
 |url=https://britastro.org/section_news_item/12p-pons-brooks-latest-lightcurve
 |access-date=9 March 2024
}}
</ref>
By 7 March the comet had brightened to magnitude&nbsp;5.5 and was located about 10&nbsp;degrees from the [[Andromeda Galaxy]].<ref>
{{cite web
 |title = Thursday 7 March 2024
 |series = Spaceweather.com Time Machine 
 |website = spaceweather.com
 |url = https://www.spaceweather.com/archive.php?view=1&day=07&month=03&year=2024
 |access-date=9 March 2024}}</ref> In the following days the comet was reported to be visible by [[naked eye]] and featured a tail about 5&nbsp;degrees long.<ref name=CBET5369>
{{cite report
 |last = Green  |first = Daniel
 |date = 15 March 2024
 |title = {{nobr|12P/Pons–Brooks}}
 |publisher = [[Central Bureau for Astronomical Telegrams]]
 |id = telegram&nbsp;5369
 |url=http://www.cbat.eps.harvard.edu/iau/cbet/005300/CBET005369.txt
}}
</ref> Another outburst occurred on April 3, with the comet brightening to a magnitude of about 3.8.<ref>{{cite web |last1=Kizer Whitt |first1=Kelly |title=Comet Pons–Brooks, the eclipse-day comet, appears to be in outburst |url=https://earthsky.org/tonight/12-p-comet-pons-brooks-outburst-millennium-falcon-bright-2024-eclipse/ |website=earthsky.org |access-date=4 April 2024 |date=4 April 2024}}</ref>
There was a [[Solar eclipse of April 8, 2024|solar eclipse on 8&nbsp;April 2024]] with the comet 25&nbsp;degrees from the Sun.<ref name=Eclipse20240408/>
The perihelion passage was on 21&nbsp;April 2024 at {{Convert|0.781|AU|e6km|abbr=unit|lk=on}} from the Sun with a velocity with respect to the Sun of 47.1&nbsp;km/s.<ref name=Horizons2024/>
The closest approach to Earth was {{time interval|2024-04-21|2024-06-02|show=d}} later on 2&nbsp;June 2024 when it was {{convert|1.55|AU|e6km|abbr=unit|lk=on}} from Earth.<ref name=Earth20240602/>
Near perihelion passage the comet was expected to brighten to about magnitude&nbsp;4.5 (around 400× brighter than the July&nbsp;2023 outburst).<ref name=Yoshida/> In early June Earth crossed the comet's orbital plane, resulting to an [[anti-tail]] becoming visible.<ref>{{cite web |title=Astro Bob: Comet 12P/Pons–Brooks grows an imaginary tail |url=https://www.duluthnewstribune.com/lifestyle/astro-bob/astro-bob-comet-12p-pons-brooks-grows-an-imaginary-tail |website=Duluth News Tribune |access-date=8 June 2024 |language=en |date=8 June 2024}}</ref>

== Orbit ==
{| class="wikitable sortable floatright" style="text-align:center; font-size: 0.9em;"
|+Earth close approach
! Date
! Distance ([[astronomical unit|AU]])
! [[Elongation (astronomy)|Solar<br/>elongation]]
|-bgcolor=#c2c2c2
|1812-Sep-21<ref name=Earth1812/> ||{{Convert|1.22|AU|e6km|abbr=unit|lk=on}} || 40°
|-bgcolor=#c2c2c2
|1884-Jan-09<ref name=kronk/> ||{{Convert|0.63|AU|e6km|abbr=unit}} || 58°
|-bgcolor=#c2c2c2
|1954-Jun-29<ref name=Earth19540629/> ||{{Convert|1.63|AU|e6km|abbr=unit}} || 38°
|-
|2024-Jun-02<ref name=Earth20240602/> ||{{Convert|1.55|AU|e6km|abbr=unit}} || 45°
|-
|2095-Aug-31<ref name=Earth2095/> ||{{Convert|1.50|AU|e6km|abbr=unit}} || 32°
|}

Libration is locked at a 6:1 resonance with Jupiter.{{sfnp|Carusi|Kresak|Perozzi|Valsecchi|1987|p=900}} The [[Tisserand's parameter|Tisserand invariant]] with respect to Jupiter (''J'') is 0.60.{{sfnp|Carusi|Kresak|Perozzi|Valsecchi|1987|p=899}}<ref name=jpldata/> Aphelion (furthest point from the Sun) is just beyond the orbit of [[Neptune]] at {{convert|33.6|AU|e9km|abbr=unit}}.

With a steep [[orbital inclination]] of 74.2° this comet does not spend a lot of time near the [[Ecliptic#Ecliptic and planets|ecliptic]]. The [[Jet Propulsion Laboratory]]'s (JPL) website shows that between the years 1900 and 2200, that the comet was and will be most significantly perturbed by [[Saturn]] on July 29, 1957. At that point it passed within 1.6AU of the [[gas giant|giant planet]]'s influence; even this approach had negligible effect.<ref name=jpldata/> The comet's orbit appears to be stable between 1740 and 2167, with no strong [[Perturbation (astronomy)|perturbations]] by any of the planets.<ref name=kronk/>{{sfnp|Carusi|Kresak|Perozzi|Valsecchi|1987|p=905}}

{{anchor|2095}}
Before the 2020 recovery, while the last observation was in 1954, Kinoshita calculated that the comet would come to a future perihelion passage (closest approach to the Sun) on 10 August 2095.<ref name="Kinoshita"/> Accounting for observations in 2020–2023, the nominal time of perihelion passage is now calculated to be 15 August 2095.<ref name="Horizons2095"/>

Kirkwood in 1884 noticed that Pons–Brooks shares elements with [[122P/de Vico|De Vico's comet of 1846]]. He suggested that the latter had calved off Pons–Brooks some centuries prior.<ref name=Kirkwood>{{cite magazine | title=The Comet of 1812 and 1883 |first=Daniel |last=Kirkwood| magazine=Popular Science Monthly |volume=24 |date=February 1884 | url=https://en.wikisource.org/wiki/Popular_Science_Monthly/Volume_24/February_1884/The_Comet_of_1812_and_1883 |pages=488–491}}</ref> Later he identified the two comets' capture into their elliptical orbits (or their parent body's capture) with their shared aphelion close to [[Neptune]] 991 CE.<ref>{{cite journal|title=The Comets 1812 I, and 1846 IV|journal=The Sidereal Messenger|date=January 1886|first=Daniel|last=Kirkwood|volume=5|pages=13–14|bibcode=1886SidM....5...13K}}</ref>

Other comets with a similar orbital period include [[13P/Olbers]], [[23P/Brorsen–Metcalf]], and [[1P/Halley]].

== Meteor showers ==
{{nobr|12P/Pons–Brooks}} is hypothesized to be the parent body of the weak December {{mvar|κ}}&nbsp;Draconids [[meteor shower]] (#336) that is active from about 29&nbsp;November to 13&nbsp;December and generates less than 2&nbsp;meteors/hour. This is the most abundant of the meteor showers predicted to be related to the comet. One more nighttime meteor shower has been tentatively associated with {{nobr|12P/Pons–Brooks,}} the northern June Aquilids, although most probably isn't the parent body.<ref name=Tomko2016/> Comet Pons–Brooks could also be the source of a meteor shower on [[Venus (planet)|Venus]], along with periodic comets {{nobr|[[122P/de Vico]]}} and {{nobr|[[27P/Crommelin]].}}<ref>
{{cite journal
 |last = Christou |first = A.A.
 |date=March 2010
 |title = Annual meteor showers at Venus and Mars: Lessons from the Earth
 |journal = [[Monthly Notices of the Royal Astronomical Society]]
 |volume=402 |issue=4 |pages=2759–2770
 |doi=10.1111/j.1365-2966.2009.16097.x |doi-access=free
 |bibcode=2010MNRAS.402.2759C
}}
</ref><ref>{{cite journal |title=Feasibility of meteor surveying from a Venus orbiter |journal=Icarus |date=2024 |doi=10.1016/j.icarus.2024.116116 |last1=Christou |first1=Apostolos A. |last2=Gritsevich |first2=Maria |volume=417 |arxiv=2405.20063 }}</ref>

== Notes ==
{{notelist|refs=

{{efn|name=Horizons|
[[JPL Horizons On-Line Ephemeris System|JPL Horizons]] ephemeris generated by JPL K242/30 (soln.date: 2023-Jul-29) has {{nobr|12P/Pons–Brooks}} coming to perihelion at 2024-Apr-21 03:16 which is about 2&nbsp;hours later than {{cite web |title=Kinoshita's 2003 solution |url=http://jcometobs.web.fc2.com/pcmtn/0012p.htm}} of 00:55.
:
The [[Minor Planet Center]]'s unperturbed [[Two-body problem|two-body]] solution (epoch 2024-05-10) gives a less accurate date of 2024-04-20.47.
:
[[JPL SBDB]] (using [[epoch (astronomy)|epoch]] {{cite web |title=2010 |url=https://archive.today/20220623124113/https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html%23/?sstr=12P&view=OPC}}) gives an even less accurate unperturbed date of 2024-Apr-19.89.
:
''See'' [[Apsis#12P|table]].
: &nbsp;
}}

{{efn|name=Outburst|
When a comet increases its [[apparent magnitude]] with a difference between 2 and 5&nbsp;magnitudes (equivalent to a [[luminosity|brightening]] of 6 to 100&nbsp;times) the event is called an {{cite web
 |title=''outburst''
 |bibcode=1975QJRAS..16..410H
|url=https://adsabs.harvard.edu/full/1975QJRAS..16..410H
}}
:
One of the more extreme example of a cometary outburst is [[17P/Holmes|{{nobr|comet 17 P / Holmes'}}]] November&nbsp;2007 brightening by about 15&nbsp;magnitudes (nearly a millionfold), described in:
::{{cite press release
 |first = A. |last = Dyer
 |date = 15 November 2007 
 |title = Hubble zooms in on [the] heart of [a] mystery comet
 |id = Release&nbsp;2007-40
 |website = hubblesite.org
 |place = Baltimore, MD
 |publisher = [[Space Telescope Science Institute]]
 |url = https://hubblesite.org/contents/news-releases/2007/news-2007-40.html
 |access-date = 2024-03-19
}}
: &nbsp;
}}

}} <!-- end of notelist -->

== References ==
{{reflist|refs=

<ref name=jpldata>
{{cite web
  |title = {{nobr|12P/Pons–Brooks }}
  |website = JPL Small-Body Database Browser (ssd.jpl.nasa.gov)
  |place = Pasadena, CA
  |publisher = [[Jet Propulsion Laboratory]]
  |quote = last observation: 2023-07-19
  |url = https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=12P&view=OPC
  |url-status=live  |access-date=2023-07-21
  |archive-url=https://archive.today/20220623124113/https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html%23/?sstr=12P&view=OPC
  |archive-date=2022-06-23
}}
</ref>

<ref name=MPC>
{{cite web
 |title = {{nobr|12P/Pons–Brooks'}} orbit
 |publisher=[[Minor Planet Center]]
 |url = http://www.minorplanetcenter.net/db_search/show_object?object_id=12P
 |access-date=2023-07-21
}}
</ref>

<ref name=Yoshida>
{{cite web
 |first = Seiichi  |last = Yoshida
 |title = {{nobr|12P/Pons–Brooks }}
 |website = aerith.net
 |series = Comet catalog
 |url=http://www.aerith.net/comet/catalog/0012P/index.html
}}
</ref>

<ref name=kronk>
{{cite web
 |last=Kronk  |first=Gary W. 
 |year = 2001–2005 
 |title = {{nobr|12P/Pons–Brooks }}
 |website = Cometography.com 
 |url = http://cometography.com/pcomets/012p.html 
 |access-date = 2009-05-07  |url-status = live
 |archive-url = https://web.archive.org/web/20080705025923/http://cometography.com/pcomets/012p.html
 |archive-date = 2008-07-05
}} [http://cometography.com Cometography (home page)]
</ref>

<ref name=Kinoshita>
{{cite web
  |first = Kazuo  |last = Kinoshita
  |date = 2003-02-22
  |title = {{nobr|12P/Pons–Brooks}} past, present and future orbital elements
  |series = Comet Orbit
  |website = jcometobs.web.fc2.com
  |url=http://jcometobs.web.fc2.com/pcmtn/0012p.htm
  |access-date = 2023-07-24
}}
</ref>

<ref name=MPEC2020-M114>
{{cite web
  |title = Observations and orbits of comets and A/ objects
  |date = 2020-06-26
  |id = MPEC 2020-M114
  |publisher = [[IAU Minor Planet Center]]
  |url = https://www.minorplanetcenter.net/mpec/K20/K20MB4.html
  |access-date = 2020-06-28
}}
</ref>

<ref name=Tomko2016>
{{cite journal
  |last1=Tomko     |first1=D.
  |last2=Neslusan  |first2=L.
  |year=2016
  |title=Meteoroid stream of {{nobr|12P/Pons–Brooks }}, December {{mvar|κ}}&nbsp;Draconids, and northern June Aquilids
  |journal=[[Astronomy & Astrophysics]]
  |volume=592  |pages=A107
  |doi=10.1051/0004-6361/201628404 |doi-access=free
  |bibcode=2016A&A...592A.107T
}}
</ref>

<ref name=Quanzhi2020>
{{cite journal
  |last1=Quanzhi |first1=Ye           |last2=Farnham |first2= Tony L.
  |last3=Knight  |first3=Matthew M.   |last4=Holt    |first4=Carrie E.
  |last5=Feaga   |first5=Lori M.
  |year=2020
  |title=Recovery of returning Halley-type comet {{nobr|12P/Pons–Brooks }} with the Lowell Discovery telescope
  |journal=[[American Astronomical Society]]
  |volume=4   |issue=7   |page=101
 |s2cid=220347511
  |doi=10.3847/2515-5172/aba2d1  |doi-access=free
  |arxiv=2007.01368 |bibcode=2020RNAAS...4..101Y
}}
</ref>

<ref name=Meyer2020>
{{cite journal
  |last1 = Meyer  |first1 = Maik           |last2 = Kobayashi |first2 = Takao
  |last3 = Nakano |first3 = Syuichi        |last4 = Green     |first4 = Daniel E.
  |year = 2020
  |title = Comet {{nobr|12P/Pons–Brooks }}: Identification with comets {{nobr|C / 1385 U{{sub|1}} }} and {{nobr|C / 1457 A{{sub|1}} }} 
  |journal = [[International Comet Quarterly]]
  |arxiv=2012.15583
}}
</ref>

<ref name=ST20231006>
{{cite web
  |first = Bob |last = King
  |date = 2023-10-06
  |title = Comet {{nobr|12P/Pons–Brooks }} flares again!
  |magazine = [[Sky & Telescope]]
  |url = https://skyandtelescope.org/astronomy-news/comet-12p-pons-brooks-flares-again/
  |access-date = 2023-10-08
}}
</ref>

<ref name=Earth1812>
{{cite web
  |title = {{nobr|12P/Pons–Brooks }} closest approach to Earth around 21&nbsp;September 1812
  |id = Using 1812 orbit solution (90000220)
  |website = [[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |publisher = [[Jet Propulsion Laboratory]]
  |place = Pasadena, CA
  |quote = (Closest Earth approach occurs when deldot flips from negative to positive.)
  |url = https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000220%27&START_TIME=%271812-Sep-18%27&STOP_TIME=%271812-Sep-24%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2720,23%27
  |access-date = 2023-07-22
}}
</ref>

<ref name=Earth19540629>
{{cite web
  |title = {{nobr|12P/Pons–Brooks }} closest approach to Earth on 29&nbsp;June 1954 (1&nbsp;hour interval)
  |website = [[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |publisher = [[Jet Propulsion Laboratory]]
  |place = Pasadena, CA
  |quote = (Closest Earth approach occurs when deldot flips from negative to positive.)
  |url = https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000223%27&START_TIME=%271954-Jun-29%27&STOP_TIME=%271954-Jun-30%27&STEP_SIZE=%271%20hours%27&QUANTITIES=%2720,23%27
  |access-date = 2023-07-22
}}
</ref>

<ref name=Eclipse20240408>
{{cite web
  |title = Horizons batch for {{nobr|12P/Pons–Brooks }}
  |id = 90000223 at Solar Eclipse on 2024-Apr-08
  |website = [[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |publisher = [[Jet Propulsion Laboratory]]
  |place = Pasadena, CA
  |quote = 
  |url = https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000223%27&START_TIME=%272024-Apr-08%2018:18%27&STOP_TIME=%272024-Apr-09%27&STEP_SIZE=%272%20days%27&QUANTITIES=%2723%27
  |access-date=2023-08-08
}}
</ref>

<ref name=Horizons2024>
{{cite web
  |title = Horizons batch for {{nobr|12P/Pons–Brooks }}
  |id = 90000223 at 2024-Apr-21 03:16 // 2024-Apr-21.136 // JPL#K242/30 Soln.date: 2023-Jul-29 
  |website = [[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |publisher = [[Jet Propulsion Laboratory]]
  |place = Pasadena, CA
  |quote = (Perihelion occurs when rdot flips from negative to positive.)
  |url = https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000223%27&START_TIME=%272024-Apr-21%27&STOP_TIME=%272024-Apr-22%27&STEP_SIZE=%2710%20minutes%27&QUANTITIES=%2719,22%27
  |url-status = live  |access-date = 2023-07-30
  |archive-url = https://web.archive.org/web/20220623123302/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000223%27&START_TIME=%272024-Apr-21%27&STOP_TIME=%272024-Apr-22%27&STEP_SIZE=%2710%20minutes%27&QUANTITIES=%2719%27
  |archive-date = 2022-06-23
}}
</ref>

<ref name=Earth20240602>
{{cite web
  |title = {{nobr|12P/Pons–Brooks }} closest approach to Earth on 2&nbsp;June 2024 (1&nbsp;hour interval)
  |id = 0000223 JPL#K242/29 Soln.date: 2023-Jul-20
  |website = [[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |publisher = [[Jet Propulsion Laboratory]]
  |place = Pasadena, CA
  |quote = (Closest Earth approach occurs when deldot flips from negative to positive.)
  |url = https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000223%27&START_TIME=%272024-Jun-01%27&STOP_TIME=%272024-Jun-04%27&STEP_SIZE=%271%20hours%27&QUANTITIES=%2720,23,39%27
  |url-status = live  |access-date = 2022-06-23
  |archive-url = https://web.archive.org/web/20220623214001/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000223%27&START_TIME=%272024-Jun-01%27&STOP_TIME=%272024-Jun-04%27&STEP_SIZE=%271+hours%27&QUANTITIES=%2720%2C39%27
  |archive-date = 2022-06-23
}} 
</ref>

<ref name=Horizons2095>
{{cite web
  |title = Horizons batch for {{nobr|12P/Pons–Brooks }}
  |id = 90000223 for August&nbsp;2095
  |website = [[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |publisher = [[Jet Propulsion Laboratory]]
  |place = Pasadena, CA
  |quote = (Perihelion occurs when rdot flips from negative to positive.)
  |url = https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%27DES%3D12P%3BCAP%27&START_TIME=%272095-Aug-01%27&STOP_TIME=%272095-Aug-31%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27
  |access-date=2023-07-24
}}
</ref>

<ref name=Earth2095>
{{cite web
  |title = {{nobr|12P/Pons–Brooks}} closest approach to Earth around 31&nbsp;August 2095
  |website = [[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |publisher = [[Jet Propulsion Laboratory]]
  |place = Pasadena, CA
  |quote = (Closest Earth approach occurs when deldot flips from negative to positive.)
  |url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000223%27&START_TIME=%272095-Aug-27%27&STOP_TIME=%272095-Sep-02%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2720,23%27
  |access-date=2023-07-22
}}
</ref>

}} <!-- end of "refs=" -->

== Sources ==
{{refbegin|colwidth=25em|small=yes}}
* {{cite journal
 |vauthors=Carusi A, Kresak L, Perozzi E, Valsecchi GB
 |year=1987
 |title=High-order librations of Halley-type comets
 |journal=[[Astronomy and Astrophysics]]
 |volume=187  |pages=899–905
 |bibcode= 1987A&A...187..899C
}}
* {{cite journal
 |first1=So-Yeon   |last1=Park
 |first2=Jong-Chul |last2=Chae
 |year=2007
 |title=Analysis of Korean historical comet records
 |journal=[[Publications of the Korean Astronomical Society]]
 |volume=22  |issue=4  |pages=151–168
 |doi= 10.5303/pkas.2007.22.4.151  |doi-access=free
 |bibcode= 2007PKAS...22..151P  |lang=ko
}}
* {{cite journal
 |last = Peng-Yoke |first = H.
 |year = 1964
 |title = Natural phenomena recorded in the ''Đai-Viêt Su{{'}}-ky Toan-Thu{{'}}'', an early Annamese historical source
 |journal = [[Journal of the American Oriental Society]]
 |volume = 84  |issue = 2  |pages = 127–149
 |doi = 10.2307/597100  |jstor = 597100}}
{{refend}}

== External links ==
* {{cite web
 |website = Comet observation database (COBS, cobs.si)
 |title = Data for {{nobr|12P/Pons–Brooks}}
 |url = https://cobs.si/comet/484
}}
* {{cite web
 |first = Maik |last = Meyer
 |title=1954 apparition lightcurve
 |series = SkyMorph
 |website = Twitter.com
 |url=https://twitter.com/skymorph/status/1277912623472955392
}}
* {{cite web
 |first = Dmitry |last = Chestnov
 |title = Comet {{nobr|12P/Pons–Brooks}} light curve
 |website = lightcurve.narod.ru
 |url = http://lightcurve.narod.ru/curves/0012p.html
}}
* {{JPL small body|name=12P/Pons–Brooks}}

{{PeriodicComets Navigator|11P/Tempel–Swift–LINEAR|13P/Olbers}}
{{Comets}}
{{2024 in space}}

{{DEFAULTSORT:Pons-Brooks, 012P}}
[[Category:Periodic comets]]
[[Category:Halley-type comets|012P]]
[[Category:Numbered comets|0012]]
[[Category:Near-Earth comets|012P]]
[[Category:Astronomical objects discovered in 1812|18120712]]
[[Category:Comets in 2024|012P]]
[[Category:Meteor shower progenitors|012P]]