| Discovery[1] | |
|---|---|
| Discovered by | Pan-STARRS 1 |
| Discovery site | Haleakalā Obs. |
| Discovery date | 8 October 2010 |
| Designations | |
| 1995 SN55[2] 2014 OK394 | |
| 3:5 resonant[3] · TNO[4] · distant[2] | |
| Orbital characteristics[4] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 2 | |
| Observation arc | 25.14 yr (9,181 days) |
| Earliestprecovery date | 20 September 1995 (Spacewatch)[5] |
| Aphelion | 49.153AU |
| Perihelion | 35.351 AU |
| 42.252 AU | |
| Eccentricity | 0.16333 |
| 274.65yr | |
| 30.889° | |
| 0° 0m 12.919s / day | |
| Inclination | 4.140° |
| 128.384° | |
| ≈ 4 January 1997[6] | |
| 247.580° | |
| Knownsatellites | 0 |
| Physical characteristics | |
| 160–280 km(est.0.08–0.20)[7][8] | |
| 6.2[2][4] | |
(523731) 2014 OK394 (provisional designation1995 SN55) is atrans-Neptunian object that orbits in theouter Solar System beyond the orbit ofNeptune. First observed as1995 SN55 bySpacewatch on 20 September 1995, it was alost minor planet with an insufficiently defined orbit with only 36 days of observations.[9] On 8 October 2010, it was rediscovered by thePan-STARRS 1 survey and later announced as2014 OK394 in July 2016.[1] It was not until November 2020 whenamateur astronomers S. Deen and K. Ly identified2014 OK394 and1995 SN55 as the same object.[10] This identification was confirmed and announced by theMinor Planet Center in January 2021.[11]
Once thought to be acentaur crossing the orbits of thegas giants,[9]1995 SN55 is now known to be a trans-Neptunian object in a 3:5orbital resonance with Neptune.[4] With an estimated diameter between 160–280 kilometers (99–170 miles), it was formerly considered one of the largest centaurs.[7][12][13]
1995 SN55 was nearperihelion 35.4 AU from the Sun when it was first observed in 1995, by astronomersNichole Danzl andArianna Gleason of theSpacewatch survey atKitt Peak Observatory in Arizona, United States.[5] It was only observed 14 times over 36 days, from 20 September to 26 October 1995.[9] The discovery observations of1995 SN55 were published and announced by theMinor Planet Center on 11 June 1999.[5] By 2020 the 3-sigma uncertainty in the heliocentric distance to the original orbit solution for1995 SN55 was approximately ±20 AU (3.0 billion km).[citation needed]
On 30 November 2020, amateur astronomers S. Deen and K. Ly identified1995 SN55 as the 3:5 resonant trans-Neptunian object(523731) 2014 OK394, which was discovered byPan-STARRS 1 in 2010.[10] The identification was published by the Minor Planet Center on 27 January 2021.[11]
2014 OK394 orbits the Sun at an average distance of 42.33 AU once every 275 years. Its orbit has aneccentricity of 0.16 and aninclination of 4° with respect to theecliptic plane. Over the course of its orbit, its distance from the Sun ranges from 35.4 AU atperihelion to 49.3 AU ataphelion.2014 OK394 is in a 3:5mean-motion orbital resonance withNeptune; for every three orbits it makes, Neptune orbits five times.[3] Its orbit has aminimum orbit intersection distance approximately 5.6 AU (840 million km; 520 million mi) from Neptune's orbital path.[4]
2014 OK394 wasnumbered by theMinor Planet Center on 25 September 2018 and received the number523731 in theminor planet catalog.[14] The alternateprovisional designation1995 SN55 was given by the Minor Planet Center on 27 January 2021 after the two objects were linked.[11] As of 2025[update], it has not beennamed.[2]
