# (230965) 2004 XA 192

Asteroid
(230965) 2004 XA 192
Properties of the orbit ( animation )
Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type SDO
DO (E SDO ),
"Distant Object"
Major semi-axis 46.813  AU
eccentricity 0.242
Perihelion - aphelion 35,466 AU - 58,159 AU
Inclination of the orbit plane 38.1 °
Length of the ascending node 328.6 °
Argument of the periapsis 132.6 °
Time of passage of the perihelion 17th March 2019
Sidereal period 320 a 3.6 M
Mean orbital velocity 4,318 km / s
Physical Properties
Medium diameter ${\ displaystyle 339 _ {- 95} ^ {+ 120} \ mathrm {km}}$
Albedo ${\ displaystyle 0 {,} 26 _ {- 0.15} ^ {+ 0.34} \ mathrm {}}$
Rotation period 7.88 ± 0.05 h (0.328 d )
Absolute brightness 4.42 ± 0.63 mag
Spectral class C.
history
Explorer Michael E. Brown
David L. Rabinowitz
Date of discovery December 12, 2004
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.

(230965) 2004 XA 192 is a large trans-Neptunian object that is classified as a near or extended scattered disk object (SDO or DO) in terms of orbital dynamics . Due to its size, the asteroid may be one of the dwarf planet candidates .

## discovery

2004 XA 192 was discovered on December 12, 2004 by a team of astronomers consisting of Mike Brown ( CalTech ), Chad Trujillo ( Gemini ) and Dave Rabinowitz ( Yale ) as part of the Near Earth Asteroid Tracking Project (NEAT) on December 1 , 2004 , 2 m Oschin Schmidt telescope discovered at Palomar Observatory ( California ). The discovery was announced on September 1, 2007 together with 2004 PF 115 , 2004 PG 115 and (303775) 2005 QU 182 , the planetoid was later given the minor planet number 230965 by the IAU .

After its discovery, XA 192 could be identified on photos up to August 29, 1989, which were also taken at the Palomar Observatory as part of the Digitized Sky Survey program (DSS), and thus its observation period was extended by 15 years. in order to calculate its orbit more precisely. Since then, the planetoid has been observed through various telescopes such as the Herschel and Spitzer space telescopes as well as earth-based telescopes. In October 2018, there were a total of 54 observations over a period of 30 years. The last observation so far was made in October 2018 at the Purple Mountain Observatory ( China ). (As of March 20, 2019)

## properties

### Orbit

2004 XA 192 orbits the sun in 320.30 years in an elliptical orbit between 35.46  AU and 58.16 AU from its center. The orbit eccentricity is 0.242, the orbit is 38.15 ° inclined to the ecliptic . The planetoid is currently 37.79 AU from the sun. He passed perihelion for the last time in 2019, so the next perihelion should take place in 2339.

Marc Buie ( DES ) classifies the asteroid as a close SDO or extended SDO (ESDO or DO ), while the Minor Planet Center does not have a specific classification; the latter classifies it as a non-SDO and generally as a “distant object” . The Johnston's Archive lists it as "other TNO" , which means it is definitely not a Cubewano or Resonantes KBO .

### Size and rotation

First estimates showed a diameter of about 600 km. Investigations in 2013 with the Herschel space telescope (instruments SPIRE and PACS) combined with the revised data from the Spitzer space telescope (instrument MIPS), however, came to the conclusion that the diameter of 2004 XA 192 is about 339 km, but with an error range of about 100 km in both directions. (P. 13) Assuming a diameter of 339 km, this results in a total surface of about 361,000 km². The apparent magnitude of 2004 XA 192 is 19.94  m .

Since it is conceivable that 2004 XA 192 is in hydrostatic equilibrium due to its size and could thus be largely round, it may meet the criteria for classification as a dwarf planet . Mike Brown assumes that 2014 WJ 509 is probably a dwarf planet, but still assumes a diameter of 549 km. Gonzalo Tancredi did not make a recommendation in 2010.

Using light curve observations , the 2004 XA 192 rotates once around its axis in 7 hours and 52.8 minutes. This means that in a 2004 XA 192 year it performs 356,309.6 self- rotations (“days”). However, this is still fraught with uncertainties, since the observation time at that time was insufficient and may also be completely wrong.

Provisions of the diameter for 2004 XA 192
year Dimensions km source
2010 666.0 Tancredi
2012 339.0 +120.0−95.0 Santos-Sanz et al. a.
2012 607.47 LightCurve DataBase
2018 549.0 Brown
The most precise determination is marked in bold .

## Individual evidence

1. a b c Marc W. Buie : Orbit Fit and Astrometric record for 230965 . SwRI (Space Science Department). Retrieved March 20, 2019.
2. a b c (230965) 2004 XA192 at the IAU Minor Planet Center (English) Retrieved March 20, 2019.
3. v ≈ π * a / period (1 + sqrt (1-e²))
4. E. Vilenius u. a .: “TNOs are cool”: A survey of the trans-Neptunian region X. Analysis of classical Kuiper belt objects from Herschel and Spitzer observations (PDF) . In: Astronomy and Astrophysics . 564, No. A35, March 25, 2014, p. 18. arxiv : 1403.6309 . doi : 10.1051 / 0004-6361 / 201322416 .
5. a b A. Thirouin et al. a .: Short-term variability of 10 trans-Neptunian objects (PDF) . In: Monthly Notices of the Royal Astronomical Society . 424, No. 4, July 9, 2012, pp. 3156-3177. arxiv : 1207.2044 . bibcode : 2012MNRAS.424.3156T . doi : 10.1111 / j.1365-2966.2012.21477.x .
6. a b LCDB Data for (230965) . MinorPlanetInfo. 2012. Retrieved March 20, 2019.
7. MPC : MPEC 2007-R03: 2004 PF115, 2004 PG115, 2004 XA192, 2005 QU182 . IAU . September 1, 2007. Accessed March 20, 2019.
8. MPC : MPEC 2008-Y74: 2004 XA192, 2006 UO321 . IAU . December 30, 2008. Retrieved March 20, 2019.
9. MPC : MPC / MPO / MPS Archive . IAU . Retrieved March 20, 2019.
10. (230965) 2004 XA192 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 20, 2019.
11. MPC : MPEC 2010-S44: Distant Minor Planets (2010 OCT.11.0 TT) . IAU . September 25, 2010. Retrieved March 20, 2019.
12. MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 20, 2019.
13. ^ Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved March 20, 2019.
14. (230965) 2004 XA192 in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
15. a b Mike Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved March 20, 2019.
16. ^ A b G. Tancredi: Physical and dynamical characteristics of icy “dwarf planets” (plutoids) (PDF) . In: International Astronomical Union (Ed.): Icy Bodies of the Solar System: Proceedings IAU Symposium No. 263, 2009 . 2010. doi : 10.1017 / S1743921310001717 . Retrieved March 1, 2019.