(523794) 2015 RR245
Orbital diagram of 2015 RR245 | |
Discovery [1] | |
---|---|
Discovered by | Pan-STARRS 1 |
Discovery site | Haleakala Obs. |
Discovery date | 15 June 2010 |
Designations | |
MPC designation | (523794) 2015 RR245 |
TNO [2] · resonant (2:9) [3][4] p-DP [5] · distant [1] | |
Orbital characteristics [2] | |
Epoch 27 April 2019 (JD 2458600.5) | |
Uncertainty parameter 3 | |
Observation arc | 13.10 yr (4,786 d) |
Earliest precovery date | 15 October 2004 |
Aphelion | 128.80 AU |
Perihelion | 33.943 AU |
81.373 AU | |
Eccentricity | 0.5829 |
734.05 yr (268,113 d) | |
323.86° | |
0° 0m 4.68s / day | |
Inclination | 7.5755° |
211.68° | |
261.02° | |
Physical characteristics | |
Mean diameter |
km 649[5] km 670[3] km 770[4] |
0.11 (assumed)[5] 0.12 (assumed)[3] | |
±0.1 3.6(Hr)[3] · 3.8[1][2] · 4.0[5] | |
|
(523794) 2015 RR245, provisional designation 2015 RR245, is a trans-Neptunian object and possible dwarf planet from the Kuiper belt in the outermost regions of the Solar System. It was discovered on 14 September 2010, by Pan-STARRS at Haleakala Observatory on the island of Maui, Hawaii, in the United States.[1] The object stays in a rare 2:9 resonance with Neptune and measures approximately 700 kilometers in diameter, which likely makes it large enough to be round.
Discovery
A first precovery of 2015 RR245 was taken at the Cerro Tololo Observatory in Chile on 15 February 2016.[1] It was first observed by a research team while poring over images that the Canada–France–Hawaii Telescope in Hawaii took in September 2015 as part of the Outer Solar System Origins Survey (OSSOS).[1][6][7] The oldest precovery is 15 October 2004.[2]
Numbering and naming
This minor planet was numbered by the Minor Planet Center on 25 September 2018 (M.P.C. 111779).[8] As of 2018, it has not been named.[1]
Physical characteristics
Diameter and albedo
Its exact size is uncertain, but the best estimate is around 670 km (420 mi) in diameter, assuming an albedo of 0.21.[3] For comparison, Pluto, the largest object in the Kuiper belt, is about 2,374 km (1,475 mi) in diameter.[6][7] Astronomer Michael Brown assumes an albedo of 0.11 and calculates at diameter of 649 kilometers, while the Johnston's Archive gives a diameter of 770 kilometers.[4][5]
Orbit
As of 2017, 2015 RR245 has a reasonably well defined orbit with an uncertainty of 4. It orbits the Sun at a distance of 33.8–128.6 AU once every 731 years and 6 months (for reference, Neptune's orbit is at 30 AU). Its orbit has an eccentricity of 0.58 and an inclination of 8° with respect to the ecliptic.[2] It will make its closest approach to the Sun in 2096.[6]
2:9 resonant TNO
Additional precovery astrometry from the Sloan Digital Sky Survey and the Pan-STARRS1 survey shows that 2015 RR245 is a resonant trans-Neptunian object, securely trapped in a 2:9 mean motion resonance with Neptune, meaning that this minor planet orbits the Sun twice in the same amount of time it takes Neptune to complete 9 orbits.[3]
2015 RR245 is unlikely to have been trapped in the 2:9 for the age of Solar System. It is much more likely that it has been hopping between various resonances and got trapped in the 2:9 resonance in the last 100 million years.[3]
References
- 1 2 3 4 5 6 7 "523794 (2015 RR245)". Minor Planet Center. Retrieved 9 October 2018.
- 1 2 3 4 5 "JPL Small-Body Database Browser: 523794 (2015 RR245)" (2017-11-22 last obs.). Jet Propulsion Laboratory. Retrieved 9 October 2018.
- 1 2 3 4 5 6 7 Bannister, Michele T.; Alexandersen, Mike; Benecchi, Susan D.; Chen, Ying-Tung; Delsanti, Audrey; Fraser, Wesley C.; et al. (December 2016). "OSSOS. IV. Discovery of a Dwarf Planet Candidate in the 9:2 Resonance with Neptune". The Astronomical Journal. 152 (6): 8. arXiv:1607.06970v2. Bibcode:2016AJ....152..212B. doi:10.3847/0004-6256/152/6/212. Retrieved 2 August 2017.
- 1 2 3 "List of Known Trans-Neptunian Objects". Johnston's Archive. 30 September 2018. Retrieved 2 October 2018.
- 1 2 3 4 5 Michael E. Brown. "How many dwarf planets are there in the outer solar system? (updates daily)". California Institute of Technology. Retrieved 30 July 2017.
- 1 2 3 "New Dwarf Planet Discovered Far Beyond Pluto's Orbit". space.com. 11 July 2016.
- 1 2 Chang, Kenneth (13 July 2016). "Astronomers Discover New Likely Dwarf Planet, the Latest of Many". New York Times. Retrieved 14 July 2016.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 9 October 2018.
External links
- MPEC 2016-N67 : 2015 RR245, Minor Planet Electronic Circular – Minor Planet Center
- New Dwarf Planet, Canada–France–Hawaii Telescope
- Kuiper Belt's Big, New, Far-Out Object, Sky & Telescope
- Outer Solar System Origins Survey (OSSOS)
- New Dwarf Planet Discovered Beyond Neptune on YouTube (time 1:01 min.)
- Discovery announcement
- (523794) 2015 RR245 at AstDyS-2, Asteroids—Dynamic Site
- (523794) 2015 RR245 at the JPL Small-Body Database