Extreme trans-Neptunian object

{{Short description|Solar system objects beyond the other known trans-Neptunian objects}}

File:Distant object orbits + Planet Nine.png, and other very distant objects along with the predicted orbit of Planet Nine{{efn-ua|The three sednoids (pink) along with the red-colored extreme trans-Neptunian object (ETNO) orbits are suspected to be aligned with the hypothetical Planet Nine while the blue-colored ETNO orbits are anti-aligned. The highly elongated orbits colored brown include centaurs and damocloids with large aphelion distances over 200 AU.}}]]An extreme trans-Neptunian object (ETNO) is a trans-Neptunian object orbiting the Sun well beyond Neptune (30 AU) in the outermost region of the Solar System. An ETNO has a large semi-major axis of at least 150–250 AU. The orbits of ETNOs are much less affected by the known giant planets than all other known trans-Neptunian objects. They may, however, be influenced by gravitational interactions with a hypothetical Planet Nine, shepherding these objects into similar types of orbits. The known ETNOs exhibit a highly statistically significant asymmetry between the distributions of object pairs with small ascending and descending nodal distances that might be indicative of a response to external perturbations.

ETNOs can be divided into three different subgroups. The scattered ETNOs (or extreme scattered disc objects, ESDOs) have perihelia around 38–45 AU and an exceptionally high eccentricity of more than 0.85. As with the regular scattered disc objects, they were likely formed as result of gravitational scattering by Neptune and still interact with the giant planets. The detached ETNOs (or extreme detached disc objects, EDDOs), with perihelia approximately between 40–45 and 50–60 AU, are less affected by Neptune than the scattered ETNOs, but are still relatively close to Neptune. The sednoid or inner Oort cloud objects, with perihelia beyond 50–60 AU, are too far from Neptune to be strongly influenced by it.

Sednoids

Among the extreme trans-Neptunian objects are the sednoids, four objects with an outstandingly high perihelion: Sedna, {{mpl|2012 VP|113}}, Leleākūhonua and {{mpl|2021 RR|205}}. Sedna and {{mp|2012 VP|113}} are distant detached objects with perihelia greater than 70 AU. Their high perihelia keep them at a sufficient distance to avoid significant gravitational perturbations from Neptune. Previous explanations for the high perihelion of Sedna include a close encounter with an unknown planet on a distant orbit and a distant encounter with a random star or a member of the Sun's birth cluster that passed near the Solar System.{{cite web |last=Wall |first=Mike |date=24 August 2011 |title=A Conversation With Pluto's Killer: Q & A With Astronomer Mike Brown |url=http://www.space.com/12711-pluto-killer-mike-brown-dwarf-planets-interview.html |website=Space.com |access-date=7 February 2016}}{{cite journal |last1=Brown |first1=Michael E. |last2=Trujillo |first2=Chadwick |last3=Rabinowitz |first3=David |date=2004 |title=Discovery of a Candidate Inner Oort Cloud Planetoid |journal=The Astrophysical Journal |volume=617 |issue=1 |pages=645–649 |arxiv=astro-ph/0404456 |bibcode=2004ApJ...617..645B |doi=10.1086/422095|s2cid=7738201 }}{{cite web |last=Brown |first=Michael E. |date=28 October 2010 |title=There's something out there – part 2 |url=http://www.mikebrownsplanets.com/2010/10/theres-something-out-there-part-2.html |website=Mike Brown's Planets |access-date=18 July 2016}}

Most distant objects from the Sun

File:Extreme transneptunian object eccentricity vs perihelion.pngs with a perihelion beyond Neptune (30 AU). While regular TNOs are located in the bottom left of the plot, an ETNO has a semi-major axis greater than 150–250 AU. They can be grouped by their perihelia into three distinct populations:

{{legend2|navy|border=1px solid navy|scattered ETNOs or ESDOs (38–45 AU)}}

{{legend2|green|border=1px solid #2B9929|detached ETNOs or EDDOs (40–45 to 50–60 AU)}}

{{legend2|red|border=1px solid #FF0000|Sednoids or inner Oort cloud objects (beyond 50–60 AU)}}

]]{{Main|List of Solar System objects most distant from the Sun}}

Notable discoveries

= Trujillo and Sheppard discoveries =

Extreme trans-Neptunian objects discovered by astronomers Chad Trujillo and Scott S. Sheppard include:

{{mpl|2013 FT|28}}, Longitude of perihelion aligned with Planet Nine, but well within the proposed orbit of Planet Nine, where computer modeling suggests it would be safe from gravitational kicks.{{cite web |url=https://www.science.org/content/article/objects-beyond-neptune-provide-fresh-evidence-planet-nine |title=Objects beyond Neptune provide fresh evidence for Planet Nine |quote=The new evidence leaves astronomer Scott Sheppard of the Carnegie Institution for Science in Washington, D.C., "probably 90% sure there's a planet out there." But others say the clues are sparse and unconvincing. "I give it about a 1% chance of turning out to be real," says astronomer JJ Kavelaars, of the Dominion Astrophysical Observatory in Victoria, Canada.|date=2016-10-25 }}
{{mpl|2014 SR|349}}, appears to be anti-aligned with Planet Nine.
{{mpl|2014 FE|72}}, an object with an orbit so extreme that it reaches about 3,000 AU from the Sun in a massively-elongated ellipse – at this distance its orbit is influenced by the galactic tide and other stars.{{cite web |url=http://www.universetoday.com/130524/planet-9-search-turning-wealth-new-objects/ |title=PLANET 9 SEARCH TURNING UP WEALTH OF NEW OBJECTS|date=2016-08-30}}{{cite web |url=http://www.iflscience.com/space/extreme-new-objects-found-at-the-edge-of-the-solar-system/ |title=Extreme New Objects Found At The Edge of The Solar System|date=30 August 2016 }}{{cite web |url=http://www.space.com/33890-planet-nine-existence-evidence-grows.html |title=The Search for Planet Nine: New Finds Boost Case for Distant World|website=Space.com |date=29 August 2016}}{{cite web |url=https://carnegiescience.edu/news/hunt-ninth-planet-reveals-new-extremely-distant-solar-system-objects |title=HUNT FOR NINTH PLANET REVEALS NEW EXTREMELY DISTANT SOLAR SYSTEM OBJECTS|date=2016-08-29}}

= Outer Solar System Origins Survey =

The Outer Solar System Origins Survey has discovered more extreme trans-Neptunian objects, including:{{cite journal |last1=Shankman |first1=Cory |display-authors=etal |year=2017 |title=OSSOS VI. Striking Biases in the detection of large semimajor axis Trans-Neptunian Objects |journal=The Astronomical Journal |volume=154 |issue=4 |page=50 |arxiv=1706.05348 |doi=10.3847/1538-3881/aa7aed |bibcode=2017AJ....154...50S|url=https://pure.qub.ac.uk/portal/en/publications/ossos-vi-striking-biases-in-the-detection-of-large-semimajor-axis-transneptunian-objects(027b7a9c-a171-42b4-9449-9355b0a255d4).html |hdl=10150/625487 |s2cid=3535702 |doi-access=free }}

{{mpl|2013 SY|99}}, which has a lower inclination than many of the objects, and which was discussed by Michele Bannister at a March 2016 lecture hosted by the SETI Institute and later at an October 2016 AAS conference.{{cite web |author=SETI Institute |date=18 March 2016 |title=Exploring the outer Solar System: now in vivid colour – Michele Bannister (SETI Talks) |url=https://www.youtube.com/watch?v=_w9N6yABAW4&t=28m17s |at=28:17 |publisher=YouTube |access-date=18 July 2016|author-link=SETI Institute }}{{cite journal |last1=Bannister |first1=Michele T. |display-authors=etal |year=2016 |title=A new high-perihelion a ~700 AU object in the distant Solar System |volume=48 |pages=113.08 |journal=American Astronomical Society, DPS Meeting #48, Id. 113.08 |bibcode=2016DPS....4811308B}}
{{mpl|2015 KG|163}}, which has an orientation similar to {{mp|2013 FT|28}} but has a larger semi-major axis that may result in its orbit crossing Planet Nine's.
{{mpl|2015 RX|245}}, which fits with the other anti-aligned objects.
{{mpl|2015 GT|50}}, which is in neither the anti-aligned nor the aligned groups; instead, its orbit's orientation is at a right angle to that of the proposed Planet Nine. Its argument of perihelion is also outside the cluster of arguments of perihelion.

Since early 2016, ten more extreme trans-Neptunian objects have been discovered with orbits that have a perihelion greater than 30 AU and a semi-major axis greater than 250 AU bringing the total to sixteen (see table below for a complete list). Most TNOs have perihelia significantly beyond Neptune, which orbits {{val|30|u=AU}} from the Sun.{{Cite journal |first=Eric |last=Hand |date=20 January 2016 |title=Astronomers say a Neptune-sized planet lurks beyond Pluto |url=http://www.sciencemag.org/news/2016/01/feature-astronomers-say-neptune-sized-planet-lurks-unseen-solar-system |journal=Science |doi=10.1126/science.aae0237 |access-date=20 January 2016|url-access=subscription }}{{cite news |last=Grush |first=Loren |date=20 January 2016 |title=Our solar system may have a ninth planet after all — but not all evidence is in (We still haven't seen it yet) |url=https://www.theverge.com/2016/1/20/10801824/ninth-planet-x-discovered-evidence |newspaper=The Verge |access-date=18 July 2016 |quote=The statistics do sound promising, at first. The researchers say there's a 1 in 15,000 chance that the movements of these objects are coincidental and don't indicate a planetary presence at all. ... 'When we usually consider something as clinched and air tight, it usually has odds with a much lower probability of failure than what they have,' says Sara Seager, a planetary scientist at MIT. For a study to be a slam dunk, the odds of failure are usually 1 in 1,744,278 . ... But researchers often publish before they get the slam-dunk odds, in order to avoid getting scooped by a competing team, Seager says. Most outside experts agree that the researchers' models are strong. And Neptune was originally detected in a similar fashion — by researching observed anomalies in the movement of Uranus. Additionally, the idea of a large planet at such a distance from the Sun isn't actually that unlikely, according to Bruce Macintosh, a planetary scientist at Stanford University.}} Generally, TNOs with perihelia smaller than {{val|36|u=AU}} experience strong encounters with Neptune.{{cite journal |last1=Batygin |first1=Konstantin |author-link1=Konstantin Batygin |last2=Brown |first2=Michael E. |author-link2=Michael E. Brown |date=2016 |title=Evidence for a distant giant planet in the Solar system |journal=The Astronomical Journal |volume=151 |issue=2 |page=22 |arxiv=1601.05438 |bibcode=2016AJ....151...22B |doi=10.3847/0004-6256/151/2/22|s2cid=2701020 |doi-access=free }}{{cite web |first=Barbara |last=Koponyás |date=10 April 2010 |title=Near-Earth asteroids and the Kozai mechanism |url=http://www.univie.ac.at/adg/Conferences/ahw5/talks/KoponysBarbara.pdf.pdf |website=5th Austrian-Hungarian Workshop in Vienna |access-date=18 July 2016}} Most of the ETNOs are relatively small, but currently relatively bright because they are near their closest distance to the Sun in their elliptical orbits. These are also included in the orbital diagrams and tables below.

= TESS data search =

Malena Rice and Gregory Laughlin applied a targeted shift-stacking search algorithm to analyze data from TESS sectors 18 and 19 looking for candidate outer Solar System objects.{{cite journal |last1=Rice |first1=Malena |last2=Laughlin |first2=Gregory |title=Exploring Trans-Neptunian Space with TESS: A Targeted Shift-stacking Search for Planet Nine and Distant TNOs in the Galactic Plane |journal= The Planetary Science Journal |volume=1 |issue=3 |pages=81 (18 pp.) |date=December 2020 |arxiv=2010.13791|doi=10.3847/PSJ/abc42c |bibcode=2020PSJ.....1...81R |s2cid=225075671 |doi-access=free }} Their search recovered known ETNOs like Sedna and produced 17 new outer Solar System body candidates located at geocentric distances in the range 80–200 AU, that need follow-up observations with ground-based telescope resources for confirmation. Early results from a survey with WHT aimed at recovering these distant TNO candidates have failed to confirm two of them.{{cite journal |last1=de la Fuente Marcos |first1=Carlos |last2=de la Fuente Marcos |first2=Raúl |last3=Vaduvescu |first3=Ovidiu | last4=Stanescu |first4=Malin |title=Distant trans-Neptunian object candidates from NASA's TESS mission scrutinized: fainter than predicted or false positives? | journal=Monthly Notices of the Royal Astronomical Society Letters |volume=513 |issue=1 |pages=L78–L82 |arxiv=2204.02230 |bibcode=2022MNRAS.513L..78D |doi=10.1093/mnrasl/slac036 | url=https://academic.oup.com/mnrasl/article-abstract/513/1/L78/6565292 |date=June 2022|doi-access=free }}{{cite web |url=https://www.ing.iac.es/PR/press/tess.html |title=Distant Trans-Neptunian Object Candidates: Fainter Than Predicted or False Positives? |date=20 May 2022}}

List

{{multiple image

|direction = horizontal

|align = left

|width2 = 500

|width1 = 375

|header = The extreme trans-Neptunian object orbits

|image2 = Extreme transneptunian object orbits.png

|image1 = Planet_nine-etnos_now-close-new.png

|alt1 = Orbits of extreme trans-Neptunian objects and Planet Nine

|alt2 = Close up of extreme trans-Neptunian objects' and planets' orbits

|caption2 = 6 original and 10 additional TNO object orbits with current positions near their perihelion in purple

|caption1 = Close up view of 13 TNO current positions

|alt=The orbits of the extreme trans-Neptunian objects are shown in various colours, with Planet Nine's orbit shown in bright green. Most of the orbits are aligned to the right of Planet Nine.

}}

rowspan=2\|Stability Relative to hypothetical Planet Nine, {{cite journal \|title=The planet nine hypothesis \|first1=Konstantin \|last1=Batygin \|first2=Fred C. \|last2=Adams \|first3=Michael E. \|last3=Brown \|first4=Juliette C. \|last4=Becker\|journal=Physics Reports \|year=2019 \|volume=805 \|pages=1–53 \|doi=10.1016/j.physrep.2019.01.009 \|arxiv = 1902.10103\|bibcode=2019PhR...805....1B \|s2cid=119248548 }} ! rowspan=2 \| {{small\|Orbital period}} {{small\|(years)}} ! rowspan=2 \| {{small\|Semimajor axis (AU)}} ! rowspan=2 \| {{small\|Perihelion (AU)}} ! rowspan=2 \| {{small\|Aphelion (AU)}} ! rowspan=2 \| {{small\|Current distance from Sun (AU)}} ! rowspan=2 \| {{small\|Eccent.}} ! rowspan=2 \| {{small\|Argum. peri}} ω (°) ! rowspan=2 \| {{small\|inclin.}} i (°) ! colspan=2 \| {{small\|Longitude of}} ! rowspan=2 \| Hv ! rowspan=2 \| Current mag. ! rowspan=2 \| {{small\|Diameter}} (km)
class="wikitable sortable" style="text-align:center" \|+ Extreme trans-Neptunian objects with perihelia greater than {{val\|30\|u=AU}} and semi-major axes greater than {{val\|250\|u=AU}}{{cite web \|author = Horizons output \|url = http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr= \|title = Barycentric Osculating Orbital Elements \|access-date = 4 February 2020 }} (Solution using the Solar System Barycenter and barycentric coordinates. (Type the target body's name, then select Ephemeris Type:Elements and Center:@0) In the second pane "PR=" can be found, which gives the orbital period in days (For Sedna as an example, the value 4.16E+06 is displayed, which is ~11400 Julian years). {{cite web \|title=MPC list of q > 30 and a > 250 \|url=http://minorplanetcenter.net/db_search/show_by_properties?perihelion_distance_min=30&semimajor_axis_min=250 \|publisher=Minor Planet Center \|access-date=5 February 2020}}{{Cite journal \|arxiv=2104.05799 \|doi=10.3847/2041-8213/abee1f \|doi-access=free \|title=Injection of Inner Oort Cloud Objects into the Distant Kuiper Belt by Planet Nine \|date=2021 \|last1=Batygin \|first1=Konstantin \|last2=Brown \|first2=Michael E. \|journal=The Astrophysical Journal Letters \|volume=910 \|issue=2 \|pages=L20 \|bibcode=2021ApJ...910L..20B }} ! rowspan=3 \| Object ! colspan=8 \| Barycentric Orbit (JD 2459600.5){{efn-ua\|Given the orbital eccentricity of these objects, different epochs can generate quite different heliocentric unperturbed two-body best-fit solutions to the semi-major axis and orbital period. For objects at such high eccentricity, the Sun's barycenter is more stable than heliocentric values. Barycentric values better account for the changing position of Jupiter over Jupiter's 12 year orbit. As an example, {{mpl\|2007 TG\|422}} has an epoch 2012 heliocentric period of ~13,500 years,{{cite web \|url=http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007TG422 \|archive-url=https://archive.today/20121213135903/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007TG422 \|url-status=dead \|title=JPL Small-Body Database Browser \|date=13 December 2012 \|archive-date=13 December 2012 }} yet an epoch 2020 heliocentric period of ~10,800 years.{{cite web \|url=http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007TG422 \|title=JPL Small-Body Database Browser \|first=Alan \|last=Chamberlin \|website=ssd.jpl.nasa.gov}} The barycentric solution is a much more stable ~11,300 years.}} ! colspan=3 \| Orbital plane ! colspan=3 \| Body
{{small\|Ascending node}} ☊ or Ω (°) ! {{small\|Perihelion}} ϖ=ω+Ω (°)
bgcolor=#ffe0e0 \| Sedna	Stable	11,400	485	76.3	893	84.5	0.84	311.3	11.9	144.2	95.6	1.3	20.7	1,000
bgcolor=#ffe0e0 \| Alicanto	Stable	5,900	327	47.3	608	48.1	0.86	326.7	25.6	66.0	32.7	6.5	23.5	200
bgcolor=#ffe0e0 \| {{mpl-\|523622\|2007 TG\|422}}	Unstable	11,260	502	35.6	969	38.5	0.93	285.6	18.6	112.9	38.4	6.5	22.5	200
Leleākūhonua	Stable	35,300	1,090	65.2	2,110	78.0	0.94	117.8	11.7	300.8	58.5	5.5	24.6	220
bgcolor=#ffe0e0 \| {{mpl\|2010 GB\|174}}	Stable	6,600	342	48.6	636	73.1	0.86	347.1	21.6	130.9	118.0	6.5	25.2	200
bgcolor=#ffe0e0 \| {{mpl\|2012 VP\|113}}	Stable	4,300	261	80.4	443	84.0	0.69	293.6	24.1	90.7	24.3	4.0	23.3	600
{{mpl\|2013 FL\|28}}	?	6,780	358	32.2	684	33.4	0.91	225.1	15.8	294.4	159.5 (*)	8.0	23.4	100
{{mpl\|2013 FT\|28}}	Metastable	5,050	305	43.4	566	55.2	0.86	40.8	17.4	217.7	258.5 (*)	6.7	24.2	200
bgcolor=#a5e1fe \| {{mpl\|2013 RF\|98}}	Unstable	6,900	370	36.1	705	37.6	0.90	311.6	29.6	67.6	19.2	8.7	24.6	70
{{mpl\|2013 RA\|109}}	?	9,950	463	46.0	880	47.4	0.90	262.9	12.4	104.8	7.6	6.1	23.1	200
{{mpl\|2013 SY\|99}}	Metastable	19,800	733	50.0	1,420	57.9	0.93	32.2	4.2	29.5	61.7	6.7	24.5	250
{{mpl\|2013 SL\|102}}	Unstable	5,590	326	38.1	614	39.3	0.88	265.4	6.5	94.6	0.0 (*)	7.0	23.2	140
{{mpl\|2014 FE\|72}}	Unstable	92,400	2,040	36.1	4,050	64.0	0.98	133.9	20.6	336.8	110.7	6.2	24.3	200
{{mpl\|2014 SX\|403}}	?	7,180	370	35.5	710	45.1	0.90	174.7	42.9	149.2	323.9 (*)	7.1	23.8	130
{{mpl\|2014 SR\|349}}	Stable	5,160	312	47.7	576	54.8	0.85	340.8	18.0	34.9	15.6	6.7	24.2	200
{{mpl\|2014 TU\|115}}	?	6,140	335	35.0	636	35.3	0.90	225.3	23.5	192.3	57.7	7.9	23.5	90
{{mpl\|2014 WB\|556}}	Metastable?	4,900	288	42.7	534	46.6	0.85	235.3	24.2	114.7	350.0 (*)	7.3	24.2	150
{{mpl\|2015 BP\|519}}{{cite conference \|url=https://aas.org/files/resources/dps49_becker.pptx \|title=Evaluating the Dynamical Stability of Outer Solar System Objects in the Presence of Planet Nine \|conference=DPS49 \|publisher=American Astronomical Society \|first=Juliette \|last=Becker \|year=2017 \|access-date=14 March 2018}}	?	9,500	433	35.2	831	51.4	0.92	348.2	54.1	135.0	123.3 (*)	4.5	21.7	550{{cite magazine \|title=The hidden hand – Could a bizarre hidden planet be manipulating the solar system \|first=Richard A. \|last=Lovett \|url=https://www.newscientist.com/issue/3156 \|magazine=New Scientist International \|issue=3156 \|page=41 \|date=16 December 2017 \|access-date=14 March 2018}}
{{mpl\|2015 DY\|248}}	?	5,400	309	34.0	585	34.4	0.89	244.6	12.9	273.1	157.7 (*)	8.3	23.9	100
{{mpl\|2015 DM\|319}} (uo5m93){{cite journal \|last1=Bannister \|first1=Michelle T. \|display-authors=etal \|title=OSSOS. VII. 800+ Trans-Neptunian Objects — The complete data release \|journal=The Astrophysical Journal Supplement Series \|date=2018 \|volume=236 \|issue=1 \|page=18 \|doi=10.3847/1538-4365/aab77a \|arxiv=1805.11740\|bibcode=2018ApJS..236...18B \|hdl=10150/628551 \|s2cid=119078596 \|doi-access=free }}	Unstable?	4,620	278	39.5	516	41.7	0.86	43.4	6.8	166.0	209.4 (*)	8.7	25.0	80?
{{mpl\|2015 GT\|50}}	Unstable	5,510	314	38.5	589	42.9	0.88	129.3	8.8	46.1	175.4 (*)	8.5	24.9	80
{{mpl\|2015 KG\|163}}	Unstable	22,840	805	40.5	1,570	40.5	0.95	32.3	14.0	219.1	251.4 (*)	8.2	24.4	100
{{mpl\|2015 RX\|245}}	Metastable	8,920	421	45.7	796	59.9	0.89	64.8	12.1	8.6	73.4	6.2	24.1	250
{{mpl\|2016 SA\|59}}	?	3,830	250	39.1	451	42.3	0.84	200.3	21.5	174.7	15.0	7.8	24.2	90
{{mpl\|2016 SD\|106}}	?	6,550	350	42.7	658	44.5	0.88	162.9	4.8	219.4	22.3	6.7	23.4	160
{{mpl\|2017 OF\|201}}	?	24,200	837	44.9	1,629	88.5	0.95	337.7	16.2	328.6	306.3 (*)	3.5	23.0	800
{{mpl\|2018 VM\|35}}	Stable	4,500	252	45.0	459	54.8	0.82	302.9	8.5	192.4	135.3 (*)	7.7	25.2	140
{{mpl\|2019 EU\|5}}	?	42,600	1,220	46.8	2,400	81.1	0.96	109.2	18.2	109.2	218.4 (*)	6.4	25.6	180
{{mpl\|2020 MQ\|53}} \| ? \|21,395 \|770 \|55.6 \|1,486 \|— \|0.93 \|18.6 \|73.4 \|287.1 \|305.7 (*) \|8.6 \| \|70
{{mpl\|2021 DK\|18}}	?	21,400	770	44.4	1,500	66.3	0.94	234.8	15.4	322.3	197.0 (*)	6.8	25.1	180
{{mpl\|2021 RR\|205}}	?	31,200	992	55.5	1,930	60.0	0.94	208.6	7.6	108.3	316.9 (*)	6.8	24.6	180
scope="row" class="unsortable" \| {{small\|Ideal elements under hypothesis}}		—	>250	>30	—	—	>0.5	—	10~30	—	2~120	—	—	—
scope="row" class="unsortable" \| Hypothesized Planet Nine\|\| \|\| {{sort\|15000\|8,000–22,000}} \|\| {{sort\|600\|400–800}} \|\| {{sort\|200\|~200}} \|\| {{sort\|1000\|~1,000}} \|\| {{sort\|1000\|~1,000?}} \|\| {{sort\|0.6\|0.2–0.5}} \|\| {{sort\|150\|~150}} \|\| {{sort\|20\|15–25}} \|\| {{sort\|91\|{{val\|91\|15}}}} \|\| {{sort\|241\|{{val\|241\|15}}}}\|\| \|\| {{sort\|22.5\|>22.5}} \|\| {{sort\|40000\|~40,000}}

{{anchor|lop}} (*) longitude of perihelion, ϖ, outside expected range;
{{small|{{legend2|#ffe0e0|border=1px #aaa solid|}}}} are the objects included in the original study by Trujillo and Sheppard (2014).{{cite journal |last1=Trujillo |first1=Chadwick A. |author-link=Chad Trujillo |last2=Sheppard |first2=Scott S. |author-link2=Scott S. Sheppard |date=2014 |title=A Sedna-like body with a perihelion of 80 astronomical units |url=http://home.dtm.ciw.edu/users/sheppard/pub/TrujilloSheppard2014.pdf |journal=Nature |volume=507 |issue=7493 |pages=471–474 |bibcode=2014Natur.507..471T |doi=10.1038/nature13156 |pmid=24670765 |s2cid=4393431 |url-access=subscription |access-date=2018-12-12 |archive-url=https://web.archive.org/web/20141216183818/http://home.dtm.ciw.edu/users/sheppard/pub/TrujilloSheppard2014.pdf |archive-date=2014-12-16 |url-status=dead }}
{{small|{{legend2|#a5e1fe|border=1px #aaa solid|}}}} has been added in the 2016 study by Brown and Batygin.{{cite web|url=http://www.findplanetnine.com/p/blog-page.html|title=Where is Planet Nine?|date=20 January 2016|website=The Search for Planet Nine|type=Blog|archive-url=https://web.archive.org/web/20160130091255/http://www.findplanetnine.com/p/blog-page.html|archive-date=30 January 2016|url-status=live}}{{cite journal |first=Alexandra |last=Witze |year=2016 |title=Evidence grows for giant planet on fringes of Solar System |journal=Nature |volume=529 |issue=7586 |pages=266–7 |bibcode=2016Natur.529..266W |doi=10.1038/529266a |pmid=26791699|doi-access=free }}{{open access}}
All other objects have been announced later.

The most extreme case is that of {{mpl|2015 BP|519}}, nicknamed Caju, which has both the highest inclination{{cite journal |title=Discovery and Dynamical Analysis of an Extreme Trans-Neptunian Object with a High Orbital Inclination |last1=Becker |first1=J. C. |collaboration=DES Collaboration |display-authors=etal |year=2018 |journal=The Astronomical Journal |volume=156 |issue=2 |pages=81 |doi=10.3847/1538-3881/aad042 |bibcode=2018AJ....156...81B |arxiv=1805.05355|s2cid=55163842 |doi-access=free }} and the farthest nodal distance; these properties make it a probable outlier within this population.{{cite journal |last1=de la Fuente Marcos |first1=Carlos |last2=de la Fuente Marcos |first2=Raúl |date=12 September 2018 |title=A Fruit of a Different Kind: 2015 BP₅₁₉ as an Outlier among the Extreme Trans-Neptunian Objects |journal=Research Notes of the AAS |volume=2 |issue=3 |pages=167 |arxiv=1809.02571 |bibcode=2018RNAAS...2..167D |doi=10.3847/2515-5172/aadfec|s2cid=119433944 |doi-access=free }}

Notes

References

{{reflist|refs=

{{cite journal |arxiv=1810.00013|last1=Sheppard|first1=Scott S.|title=A New High Perihelion Trans-Plutonian Inner Oort Cloud Object: 2015 TG387 |last2=Trujillo |first2=Chadwick A. |last3= Tholen |first3=David J.|last4=Kaib |first4=Nathan |journal=The Astronomical Journal|year=2019|volume=157|issue=4|page=139|doi=10.3847/1538-3881/ab0895|bibcode=2019AJ....157..139S|s2cid=119071596 |doi-access=free }}

{{cite journal |last1=de la Fuente Marcos |first1=Carlos |last2=de la Fuente Marcos |first2=Raúl |title=Peculiar orbits and asymmetries in extreme trans-Neptunian space |journal=Monthly Notices of the Royal Astronomical Society |url=https://academic.oup.com/mnras/article-abstract/506/1/633/6307523|volume=506 |issue=1 |pages=633–649 |arxiv=2106.08369 |bibcode=2021MNRAS.506..633D |doi=10.1093/mnras/stab1756|date=1 September 2021 |doi-access=free }}

{{cite journal |last1=de la Fuente Marcos |first1=Carlos |last2=de la Fuente Marcos |first2=Raúl |title=Twisted extreme trans-Neptunian orbital parameter space: statistically significant asymmetries confirmed |journal=Monthly Notices of the Royal Astronomical Society Letters |url=https://academic.oup.com/mnrasl/article-abstract/512/1/L6/6524836 |volume=512 |issue=1 |pages=L6–L10 |arxiv=2202.01693 |bibcode=2022MNRAS.512L...6D |doi=10.1093/mnrasl/slac012 |date=1 May 2022|doi-access=free }}

}}

External links

[https://web.archive.org/web/20150325061501/http://home.dtm.ciw.edu/users/sheppard/inner_oort_cloud/sednoids.html Known extreme outer solar system objects], Scott Sheppard, Carnegie Science Center
[http://home.dtm.ciw.edu/users/sheppard/extreme_objects/ Hunt for Ninth Planet Reveals New Extremely Distant Solar System Objects], Scott Sheppard, Carnegie Science Center
[http://www.johnstonsarchive.net/astro/tnoslist.html List of Known Trans-Neptunian Objects] (including ESDOs and EDDOs), Robert Johnston, Johnston's Archive

Category:Distant minor planets

Category:Neptune

Category:Solar System