15P/Finlay
{{Short description|Periodic comet with 6 year orbit}}
{{Infobox comet
| name=15P/Finlay
| image = Comet Finlay in 1960 by the US Naval Observatory.jpg
| caption = Comet Finlay photographed from the US Naval Observatory on 26 September 1960
| discoverer = William Henry Finlay
| discovery_date = 26 September 1886
| mpc_name = P/1886 S1, P/1893 K1
| designations = {{unbulleted|1886 VII, 1893 III, 1906 V|1919 II, 1926 V, 1953 VII|1960 VIII, 1967 IX, 1974 X|1981 XII, 1988 IX|1886e, 1893a, 1906d|1919d, 1926d, 1953i|1960d, 1967g, 1974d|1981e, 1988f}}
| epoch=2014-Dec-09
(JD 2457000.5)
| Earth_moid = {{Convert|0.009|AU|e6km|abbr=unit}}
| Jupiter_moid = {{Convert|0.16|AU|e6km|abbr=unit}}
| semimajor=3.488 AU
| perihelion=0.976 AU
| aphelion=6.019 AU
| eccentricity=0.7202
| period=6.51 a
| inclination=6.799°
| last_p=July 13, 2021
December 27, 2014
June 22, 2008
| next_p=2028-Feb-09
2034-Sep-08
2041-Apr-03
2047-Oct-25
2054-May-02
2060-Oct-03
| dimensions=1.8 km (uncertain){{cite book|author1=M. Festou|author2=H. U. Keller|author3=Harold A. Weaver|title=Comets II|url=https://books.google.com/books?id=AHF9ZraafV8C&pg=PA242|year=2004|publisher=University of Arizona Press|isbn=978-0-8165-2450-1|page=242}}
}}
Comet Finlay is a periodic comet with an orbital period of 6 years discovered by William Henry Finlay (Royal Observatory, Cape of Good Hope, South Africa) on September 26, 1886. The next perihelion passage is July 13, 2021 when the comet will have a solar elongation of 54 degrees at approximately apparent magnitude 10. It last came to perihelion on December 27, 2014, at around magnitude 10. Of the numbered periodic comets, the orbit of 15P/Finlay has one of the smallest minimum orbit intersection distances with the orbit of Earth (E-MOID). In October 2060 the comet will pass about 5 million km from Earth.
Description
| class=wikitable style="text-align:center; font-size:11px; float:left; margin-right:12px" | |
| style="background-color: #222; color: white; font-size: smaller;"
| colspan="8" style="text-align:center;"|Perihelion distance | |
| Epoch | Perihelion (AU) |
|---|---|
| 1866 | 1.0 |
| 1906 | 0.96 |
| 1919 | 1.0 |
| 1981 | 1.1 |
| 2008 | 0.97 |
| 2021 | 0.99 |
| 2028 | 1.0 |
When the first orbit calculations were made in 1886, there was a similarity between this orbit and that of Francesco de Vico's lost periodic comet of 1844 (54P/de Vico-Swift-NEAT). Lewis Boss (Dudley Observatory, Schenectady, United States) noted large discrepancies between the orbits and after further observations concluded that de Vico's comet could not be the same as Finlay's.
During the 1906 apparition the comet brightened to magnitude 6. In 1910 a close pass with Jupiter increased the orbital period, in 1919 the path was off predictions and a new comet discovered by Sasaki (Kyoto Observatory, Japan) on October 25, 1919, was discovered to be Finlay's.
The magnitude of the comet declined after 1926, and it was not until 1953 that it has been observed on every return.
2014–2015
During the 2014 perihelion passage the comet outburst on 16 December 2014 from magnitude 11 to magnitude 9 becoming bright enough to be seen in common binoculars with a 50 mm objective lens. On December 23, 2014, 15P and Mars were only 1/6 of a degree apart in the sky after sunset. But by December 23, 2014, the comet had dimmed considerably since the outburst. On 16 January 2015, the comet outburst to magnitude 8.
2060
15P/Finlay currently has an Earth-MOID of {{convert|0.009|AU|km mi|abbr=on|lk=on}}. The comet will come to perihelion six more times and then on October 22, 2060, the comet will pass roughly {{convert|0.0334|AU|e6km e6mi|abbr=unit}} from Earth with an uncertainty region of about ±2300 km. This will be one of the closest comet approaches to Earth.[http://wirtanen.astro.umd.edu/close_approaches.shtml Comet Close Approaches to the Earth]
Arids meteor shower
Debris ejected during the 1995 perihelion passage generated a meteor shower on 29–30 September 2021 radiating from the southern constellation of Ara. More outbursts are expected on 7 October 2021 from the 2008 and 2014 streams.
References
{{reflist
| refs =
|title=15P/Finlay Orbit
|url=http://www.minorplanetcenter.net/db_search/show_object?object_id=15P
|publisher=Minor Planet Center
|access-date=2014-06-21}}
|date=2011-11-05
|title=15P/Finlay (NK 2161)
|publisher=OAA Computing and Minor Planet Sections
|author=Syuichi Nakano
|author-link=Syuichi Nakano
|url=http://www.oaa.gr.jp/~oaacs/nk/nk2161.htm
|access-date=2012-02-18}}
|date=2016-06-11
|title=15P/Finlay
|publisher=Seiichi Yoshida's Comet Catalog
|author=Seiichi Yoshida
|url=http://www.aerith.net/comet/catalog/0015P/index.html
|access-date=2020-07-20}}
|title=15P/Finlay
|first=Gary W |last=Kronk |author-link=Gary W. Kronk
|work=Cometography
|url=http://cometography.com/pcomets/015p.html
|access-date=2007-01-31}}
|title=Comet Finlay in Bright Outburst, Visible in Small Telescopes
|author=Bob King
|publisher=Universe Today
|url=http://www.universetoday.com/117449/comet-finlay-in-bright-outburst-visible-in-small-telescopes/
|access-date=2014-12-20|date=2014-12-18}}
|type=last observation: 2022-03-03
|title=JPL Close-Approach Data: 15P/Finlay
|url=https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=15p&view=OPC
|archive-url=https://web.archive.org/web/20170220010657/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=15P;cad=1
|archive-date=2017-02-20
|url-status=live
|access-date=2022-06-16}}
|title=24324Re: [comets-ml] Re: Possible another outburst of 15P/Finlay?
|author=Michael Mattiazzo
|publisher=Yahoo: comet-ml
|url=https://groups.yahoo.com/neo/groups/comets-ml/conversations/messages/24324
|archive-url=https://archive.today/20150119001956/https://groups.yahoo.com/neo/groups/comets-ml/conversations/messages/24324
|url-status=dead
|archive-date=January 19, 2015
|access-date=2015-01-17}}
|title=Horizons Batch for 15P/Finlay (90000257) on 2028-Feb-09
|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=%2790000257%27&START_TIME=%272028-Feb-07%27&STOP_TIME=%272028-Feb-12%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27
|accessdate=2022-06-16}} (JPL#K213/16 Soln.date: 2022-Mar-09)
|title=Horizons Batch for 15P/Finlay (90000257) on 2060-Oct-03
|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=%2790000257%27&START_TIME=%272060-Sep-30%27&STOP_TIME=%272060-Oct-07%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27
|accessdate=2022-06-16}} (JPL#K213/16 Soln.date: 2022-Mar-09)
|title=Horizons Batch for 2060-Oct-22 Earth approach
|publisher=JPL Horizons
|url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000257%27&START_TIME=%272060-Oct-22%2017:00%27&STOP_TIME=%272060-Oct-22%2018:00%27&STEP_SIZE=%2710%20minutes%27&QUANTITIES=%2720,39%27
|archive-url=https://web.archive.org/web/20220616142743/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000257%27&START_TIME=%272060-Oct-22+17%3A00%27&STOP_TIME=%272060-Oct-22+18%3A00%27&STEP_SIZE=%2710+minutes%27&QUANTITIES=%2720%2C39%27
|archive-date=2022-06-16
|url-status=live
|accessdate=2022-06-16}}
|title=JPL Small-Body Database Search Engine: numbered comets
|publisher=JPL Solar System Dynamics
|url=https://ssd.jpl.nasa.gov/sbdb_query.cgi?obj_group=all;obj_kind=com;obj_numbered=num;OBJ_field=0;ORB_field=0;table_format=HTML;max_rows=100;format_option=comp;c_fields=AcBgBiBjBnBqBsCiCkBtAp;.cgifields=format_option;.cgifields=obj_kind;.cgifields=obj_group;.cgifields=obj_numbered;.cgifields=ast_orbit_class;.cgifields=table_format;.cgifields=com_orbit_class&query=1&c_sort=BtA
|access-date=2020-07-27}}
|title=Electronic Telegram No. 5046 : ARID METEORS 2021
|url=http://www.cbat.eps.harvard.edu/cbet/005000/CBET005046.txt
|publisher=Central Bureau for Astronomical Telegrams
|access-date=2021-10-01}}
}}
External links
- {{JPL Small Body|id=1000027}}
- [https://minorplanetcenter.net/cgi-bin/returnprepeph.cgi?d=c&o=0015P Elements and Ephemeris for 15P/Finlay] – Minor Planet Center
- [http://cometography.com/pcomets/015p.html 15P at Kronk's Cometography]
- [http://jcometobs.web.fc2.com/pcmtn/0015p.htm 15P at Kazuo Kinoshita's Comets]
- [http://www.aerith.net/comet/catalog/0015P/index.html 15P at Seiichi Yoshida's Comet Catalog]
- [http://cometbase.net/en/observation/listObserv/253 15P at CometBase database]
- [https://archive.today/20140629143416/https://groups.yahoo.com/neo/groups/comets-ml/conversations/messages/23644 2014 June 22 recovery at apmag 20] (comets-ml)
- [http://i727.photobucket.com/albums/ww271/Rob_Kau/15P18Dec2014text.jpg~original 15P/Finlay on 18 Dec 2014] (200mm lens F5.6 / Rob Kaufman of Australia)
- [https://archive.today/20141218171031/http://gloria.fzu.cz/datas/users/2/15p_animation_17_18_december_2.gif Animation of 15P/Finlay by FRAM (0.3-m f/10 reflector + CCD, MPC I47), 17th and 18th Dec 2014] (Martin Masek)
{{PeriodicComets Navigator|14P/Wolf|16P/Brooks}}
{{Comets}}
{{DEFAULTSORT:Finlay, 015P}}