(524531) 2002 XH ₉₁

Asteroid 2002 XH 91
Properties of the orbit ( animation ) Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type	CKBO ( "Cold" ), "Distant Object"
Major semi-axis	43,752  AU
eccentricity	0.094
Perihelion - aphelion	39.658 AU - 47.846 AU
Inclination of the orbit plane	5 °
Length of the ascending node	80.6 °
Argument of the periapsis	186.5 °
Time of passage of the perihelion	September 29, 2134
Sidereal period	289 a 4.8 M
Mean orbital velocity	4.466 km / s
Physical Properties
Medium diameter	approx. 298 km
Dimensions	6:50 ± 0:40  ·  10 18 kg
Albedo	0.08-0.10
Absolute brightness	5.7 - 5.8 mag
Spectral class	C.
history
Explorer	Lawrence H. Wasserman David E. Trilling Robert L. Millis
Date of discovery	4th December 2002
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.

(524531) 2002 XH ₉₁ is a large trans-Neptunian object in the Kuiper Belt , which is classified as Cubewano (CKBO) in terms of railway dynamics . Due to its size, the asteroid is one of the dwarf planet candidates . 2002 XH ₉₁ has a natural companion named S / 2008 (524531) 1 , which is about two-thirds the diameter of the asteroid . Since both celestial bodies revolve around the common center of gravity , the system can also be understood as a double asteroid system.

discovery

2002 XH ₉₁ was on 4 December 2002 by a team of astronomers consisting of Larry Wasserman, David Robert Trilling and Millis, with the 4.0-m-reflector telescope at Kitt Peak National Observatory ( Arizona discovered). The discovery was announced on January 2, 2003 along with the TNO 2002 XD ₉₁ , 2002 XE ₉₁ , 2002 XF ₉₁ , 2002 XG _91, and 2002 XJ ₉₁ . the planetoid was given the provisional designation 2002 XH ₉₁ and on May 18, 2019, the minor planet number 524531 from the IAU .

The observation arc of the asteroid begins with the official observation on December 4, 2002. Since then, the asteroid has been observed through various earth-based telescopes. In December 2018 there were a total of 60 observations over a period of 16 years. The last observation so far was carried out in February 2018 at the Pan-STARRS telescope (PS1) ( Maui ). (As of March 24, 2019)

properties

Orbit

2002 XH ₉₁ orbits the sun in 289.40 years on a slightly elliptical orbit between 39.65  AU and 47.85 AU from its center. The eccentricity of the orbit is 0.094, the orbit is inclined at 5.00 ° to the ecliptic . The planetoid is currently 47.17 AU from the Sun. The next time it passes through perihelion in 2134, the last perihelion should have been in 1845.

Marc Buie ( DES ) classifies the planetoid as Cubewano , whereby it belongs to the orbital dynamics "cold" classical KBO , 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” .

size

A diameter of 298 km is currently assumed, based on a reflectivity of 8% and an absolute brightness of 5.8  ^m . Based on this diameter, the total area is about 279,000 km². The apparent magnitude of 2002 XH ₉₁ is 22.41  ^m .

Since it is conceivable that 2002 XH ₉₁ 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 believes that it is in 2002 XH ₉₁ to perhaps is a dwarf planet.

Provisions of the diameter for 2002 XH ₉₁

year	Dimensions km	source
2015	304.44	LightCurve DataBase
2018	352.0 298.0	Johnston
2018	329.0	Brown
The most precise determination is marked in bold .

moon

→ Main article : S / 2008 (524531) 1

On May 27, 2009, a team of astronomers led by Keith S. Noll announced the discovery of a companion around 185 km in diameter, which was tracked down using images from the Hubble Space Telescope . It circles the common barycenter with 2002 XH ₉₁ in 371.1 days at a mean distance of 22400 ± 400 km. The system mass was determined to be 6.5  ·  10 ¹⁸ .

The 2002 XH ₉₁ system at a glance:

Components	Physical parameters			Path parameters				discovery
Surname	Throughput diameter (km)	Relative size %	Mass (kg)	Major semi-axis (km)	Orbital time (d)	eccentricity	Inclination to the 2002 XH 91 equator	Date of discovery Date of publication
2002 XH 91	298.0	100.00	6.5  ·  10 18	-	-	-	-	December 4, 2002 January 2, 2003 0
S / 2008 (524531) 1 (2002 XH 91 I)	185.0	62.08	?	24400	371.1	0.71	3.0	November 8, 2008 May 27, 2009

See also

• List of trans-Neptunian objects
• List of dwarf planets of the solar system
• List of asteroids
• List of moons from asteroids

Web links

• How many dwarf planets are there in the outer solar system? Current list of the largest TNOs from Mike Brown
• Free the dwarf planets! Mike Brown's column on the IAU and the dwarf planets regarding their classifications (23 August 2011)

Individual evidence

1. ^ ^{A b} Marc W. Buie : Orbit Fit and Astrometric record for 02XH91 . SwRI (Space Science Department). Retrieved March 24, 2019.
2. ↑ ^{a b c} Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Accessed March 24, 2019.
3. ↑ ^{a b c} (524531) 2002 XH91 at the IAU Minor Planet Center (English) Accessed March 24, 2019.
4. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
5. ↑ ^{a b} LCDB Data for 2002 XH91 . MinorPlanetInfo. 2009. Retrieved March 24, 2019.
6. ↑ MPC : MPEC 2003-A05: 2002 XD91, 2002 XE91, 2002 XF91, 2002 XG91, 2002 XH91, 2002 XJ91 . IAU . January 2, 2003. Retrieved March 24, 2019.
7. ↑ (524531) 2002 XH91 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 24, 2019.
8. ↑ MPC : MPEC 2010-S44: Distant Minor Planets (2010 OCT.11.0 TT) . IAU . September 25, 2010. Accessed March 24, 2019.
9. ↑ MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 24, 2019.
10. ↑ (524531) 2002 XH91 in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
11. ↑ ^{a b} Mike Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved March 24, 2019.
12. ↑ IAU : IAUC No. 9046: 2002 XH_91, V1280 Scorpii . In: Central Bureau for Astronomical Telegrams . May 27, 2009. bibcode : 2009IAUC.9046 .... 1N .
13. ^ Wm. R. Johnston: Asteroids with Satellites - 2002 XH91 . Johnston's Archives. September 20, 2014. Accessed March 24, 2019.