(523794) 2015 RR 245

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Asteroid
(523794) 2015 RR 245
Properties of the orbit ( animation )
Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type RKBO 2: 9 or
SDO ,
"Distant Object"
Major semi-axis 81,373  AU
eccentricity 0.583
Perihelion - aphelion 33.943 AU - 128.803 AU
Inclination of the orbit plane 7.6 °
Length of the ascending node 211.7 °
Argument of the periapsis 261 °
Time of passage of the perihelion January 2, 2093
Sidereal period 734 a 0.6 M.
Mean orbital velocity 3.275 km / s
Physical Properties
Medium diameter 670 km
Albedo 0.09-0.10
Absolute brightness 3.8 - 4.2 mag
history
Explorer Michele T. Bannister
John J. Kavelaars
Brett J. Gladman
Jean-Marc Petit
Todd Burdulis
Date of discovery September 9, 2015
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.

(523794) 2015 RR 245 is a large trans-Neptunian object that is classified as a resonant KBO (2: 9 resonance) or as a scattered disc object (SDO). Because of its size, the asteroid is a dwarf planet candidate .

discovery

2015 RR 245 was discovered on September 9, 2015 by a team of astronomers consisting of Michele Bannister, JJ Kavelaars , Brett Gladman , Jean-Marc Petit and Todd Burdulis of the 3.6 m CFHT telescope (Outer Solar System Origins Survey Project ( OSSOS) at the Mauna Kea Observatory , Hawaii ), discovered on photographic images from June 15, 2010 of the 1.8 m Pan STARRS telescope (PS1) at the Haleakalā Observatory ( Maui ). The discovery was announced on July 10, 2016 the asteroid was on 25 September 2018 the IAU , the Minor Planet -number five hundred and twenty-three thousand seven hundred and ninety-four .

After its discovery, RR 245 could be traced back to 2015 in photos taken at the Cerro Tololo Observatory ( Chile ) on October 15, 2004, extending its observation period by 11 years in order to calculate its orbit more precisely. Since then, in 2015 RR 245 could also be identified between 2008 and 2016 on images from the Sloan Digital Sky Survey and Pan-STARRS projects and other earth-based telescopes. In October 2018 there were a total of 183 observations over a period of 14 years. The last observation to date was again carried out in November 2017 at the Mauna Kea Observatory. (As of March 14, 2019)

properties

2015 orbit RR 245

Orbit

2015 RR 245 orbits the sun in 734.05 years on a strongly elliptical orbit between 33.94  AU and 128.80 AU from its center. The orbit eccentricity is 0.583, the orbit is 7.58 ° inclined to the ecliptic . The point closest to the Sun is still outside the orbit of Neptune , whose orbit it therefore never crosses. The planetoid is currently 62.78 AU from the Sun. He will next pass perihelion in 2093, so the last perihelion should have occurred in 1359.

2015 RR 245 is in a rare, stable 2: 9 orbit resonance with Neptune . However, this does not seem to have been the case through the entire age of the solar system; it is more likely that the asteroid previously wandered between different resonances and was trapped in the current 2: 9 resonance for the past 100 million years.

Marc Buie ( DES ) classifies the planetoid as RKBO , while the Minor Planet Center classifies it as an SDO and more generally as a “Distant Object” .

size

The size of the object is currently estimated at 670 km in diameter; this value is based on an assumed reflectivity of 21%. Based on this diameter, the total surface area is around 1,410,000 km 2 . The apparent magnitude of the 2015 RR 245 is 22.24  m .

This makes it a possible candidate for classification as a dwarf planet by the IAU . A classification as a dwarf planet has not yet been made, so press reports to the contrary were premature. Such a classification can only be expected if proof of sufficient mass can be provided, as a result of which the object forms a hydrostatic equilibrium due to its own gravity and thus has an approximately round shape. Mike Brown estimates the asteroid's diameter to be 615 km based on an assumed albedo of 10% and an absolute brightness of 4.2  m . Brown assumes that 2001 UR 163 is most likely a dwarf planet.

Provisions of the diameter for 2015 RR 245
year Dimensions km source
2016 670.0 Bannister et al. a.
2018 770.0 Johnston
2018 615.0 Brown
The most precise determination is marked in bold .

See also

Web links

Commons : (523794) 2015 RR245  - Collection of Images, Videos and Audio Files

Individual evidence

  1. ^ A b Marc W. Buie : Orbit Fit and Astrometric record for 523794 . SwRI (Space Science Department). Retrieved March 14, 2019.
  2. ↑ a b M. Bannister u. a .: OSSOS: IV. Discovery of a dwarf planet candidate in the 9: 2 resonance with Neptune (PDF) . In: The Astronomical Journal . 152, No. 6, July 23, 2016, p. 212, 8. arxiv : 1607.06970 . bibcode : 2016AJ .... 152..212B . doi : 10.3847 / 0004-6256 / 152/6/212 .
  3. ↑ a b c Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved March 14, 2019.
  4. ↑ a b MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 14, 2019.
  5. ↑ a b c (523794) 2015 RR245 at the IAU Minor Planet Center (English) Retrieved on March 14, 2019.
  6. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
  7. ↑ Welcome to the Outer Solar System Origins Survey . OSSOS. 2015. Accessed March 14, 2019.
  8. ↑ MPC : MPEC 2016-N67: 2015 RR245 . IAU . July 10, 2016. Accessed March 14, 2019.
  9. ↑ Canada-France-Hawaii Telescope (CFHT): New Distant Dwarf Planet Beyond Neptune . IAU . July 11, 2016. Retrieved March 14, 2019.
  10. ↑ MPC : MPC / MPO / MPS Archive . IAU . Retrieved March 14, 2019. Reference there: MPC 111779
  11. ↑ (523794) 2015 RR245 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 14, 2019. Template: JPL Small-Body Database Browser / Maintenance / Alt
  12. ↑ (523794) 2015 RR245 in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
  13. ↑ Tilmann Althaus: Dwarf Planet or Not? . Spektrum.de. July 12, 2016. Retrieved March 14, 2019.
  14. ↑ a b Mike Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved February 9, 2019.