(278361) 2007 JJ ₄₃

Asteroid (278361) 2007 JJ 43
Properties of the orbit ( animation ) Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type	SDO , "Distant Object"
Major semi-axis	48.435  AU
eccentricity	0.167
Perihelion - aphelion	40,359 AU - 56,511 AU
Inclination of the orbit plane	12 °
Length of the ascending node	272.6 °
Argument of the periapsis	7 °
Time of passage of the perihelion	June 29, 2036
Sidereal period	337 a 1 M
Mean orbital velocity	4.245 km / s
Physical Properties
Medium diameter	${\displaystyle 610_{-140}^{+170}\mathrm {km} }$
Albedo	${\displaystyle 0{,}13_{-0,07}^{+0,09}\mathrm {} }$
Rotation period	6.048 ± 0.018 h (0.252 d ) or 12.097 ± 0.036 h (0.504 d )
Absolute brightness	4.044 ± 0.019 - 4.170 ± 0.020 mag
Spectral class	C B-R = 1.610 ± 0.020
history
Explorer	Megan E. Schwamb Michael E. Brown David L. Rabinowitz
Date of discovery	May 14, 2007
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.

(278361) 2007 JJ ₄₃ is a large trans-Neptunian object in the Kuiper Belt , which is classified as a Scattered Disk Object (SDO) in terms of orbital dynamics . Because of its size, the asteroid is a dwarf planet candidate .

discovery

(278361) 2007 JJ ₄₃ was discovered on May 14, 2007 by a team of astronomers consisting of Meg Schwamb, Mike Brown and Dave Rabinowitz of the California Institute of Technology (CalTech) at the 1.2 m Oschin Schmidt telescope of the Palomar Observatory ( California ) discovered. The discovery was announced on July 5, 2007 along with the 2007 JF ₄₃ , 2007 JH _43, and 2007 JK ₄₃ . He received on 24 June 2011 by the IAU , the Minor Planet -number two hundred seventy-eight thousand three hundred sixty-one .

After its discovery, in 2007 JJ _{43 could be identified} in photos from May 10, 2002, which were also taken at the Palomar Observatory as part of Near Earth Asteroid Tracking (NEAT), and thus its orbit could be calculated more precisely. Since then, the asteroid has been observed through various telescopes such as the Kepler Space Telescope as well as Earth-based telescopes. In April 2017, there were 205 observations over a period of 14 years from 9 oppositions. The last observation so far was carried out in July 2015 on the Pan-STARRS telescope. (As of March 4, 2019)

properties

Orbit

In 2007 JJ ₄₃ , the Sun will orbit in 337.09 years on a slightly elliptical orbit between 40.36  AU and 56.51 AU from its center. The orbital eccentricity is 0.167, the orbit is 12.02 ° inclined to the ecliptic . The planetoid is currently 40.96 AU from the sun. It will next pass through perihelion in 2036, so the last perihelion should have occurred in 1699.

Marc Buie ( DES ) classifies the planetoid as SDO , 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

It is currently assumed to have a diameter of 610 km, making the asteroid a size comparable to Ixion . This value is based on an assumed reflectivity of 13% and an absolute brightness of 3.9 ^m ; however, this is fraught with some uncertainties, since the estimates range from 346 to 730 km due to the still unknown albedo. The values ​​for the absolute brightness also vary from 3.2 to 4.5 ^m .

Since it can be assumed that 2007 JJ ₄₃ is in hydrostatic equilibrium due to its size and must therefore be largely round, it would have to meet the criteria for classification as a dwarf planet. Mike Brown assumes that 2007 JJ ₄₃ is most likely a dwarf planet.

Based on light curve observations in 2015, 2007 JJ ₄₃ rotates once around its axis in 12 hours and 5.82 minutes. From this it follows that in a 2007 JJ ₄₃ year it performs 244272.7 self- rotations (“days”). A second result from the same team of astronomers, however, suggested a rotation period of 6 hours and 2.88 minutes that was half as long, which would practically double the number of quaoar days with 488,585.7 revolutions. However, both statements are still subject to some uncertainties, as the observation time at that time was insufficient and the error rate is around 30%.

Provisions of the diameter for 2007 YY ₄₃

year	Dimensions km	source
2015	610.0 +170.0−140.0	Pál u. a.
2015	529.08	LightCurve DataBase
2018	558.0	Johnston
2018	513.0	Brown
The most precise determination is marked in bold .

surface

Nothing is known about the surface quality, but 2007 JJ _{43 is} one of the 20 brightest TNOs, which is more likely to be due to the size than to a particularly bright surface. The apparent magnitude of 2007 JJ ₄₃ is 20.80  ^m . Based on a diameter of 610 km, the total surface area is about 1,169,000 km².

Since no moon has been found in 2007 JJ ₄₃ so far, the mass cannot be calculated directly. According to Mike Brown, observations by the Keck Observatory do not show a large moon, but the planetoid could still have one - or several - small ones.

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} M. Buie : Orbit Fit and Astrometric record for 278361. SwRI (Space Science Department), accessed on March 4, 2019 . 
2. ↑ ^{a b c} (278361) 2007 JJ43 at the IAU Minor Planet Center (English) Retrieved March 4, 2019.
3. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
4. ↑ ^{a b c d e f g} A. Pál u. a .: Pushing the limits: K2 observations of the trans-Neptunian objects 2002 GV ₃₁ and (278361) 2007 JJ ₄₃ . In: The Astrophysical Journal Letters . 804, No. 2, May 12, 2015, p. L45. arxiv : 1504.03671 . bibcode : 2015ApJ ... 804L..45P . doi : 10.1088 / 2041-8205 / 804/2 / L45 .
5. ↑ ^{a b} N. Peixinho u. a .: The bimodal colors of Centaurs and small Kuiper belt objects (PDF) . In: Astronomy and Astrophysics . 546, No. A86, June 14, 2012, p. 12. arxiv : 1206.3153 . bibcode : 2012A & A ... 546A..86P . doi : 10.1051 / 0004-6361 / 201219057 .
6. ↑ S. Benecchi, S. Sheppard : Light Curves of 32 Large Transneptunian Objects (PDF) . In: The Astronomical Journal . 145, No. 5, January 24, 2013, p. 124, 19. arxiv : 1301.5791 . bibcode : 2013AJ .... 145..124B . doi : 10.1088 / 0004-6256 / 145/5/124 .
7. ↑ ^{a b} LCDB Data for (278361) . MinorPlanetInfo. 2015. Accessed March 4, 2019.
8. ↑ MPC : MPEC 2007-N14: 2007 JF43, 2007 JH43, 2007 JJ43, 2007 JK43 . IAU . July 5, 2007. Retrieved March 15, 2019.
9. ↑ MPC : MPC / MPO / MPS Archive . IAU . Retrieved March 4, 2019.
10. ↑ ^{a b} (278361) 2007 JJ43 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 4, 2019.
11. ↑ MPC : MPEC 2010-S44: Distant Minor Planets (2010 OCT.11.0 TT) . IAU . September 25, 2010. Accessed March 4, 2019.
12. ↑ MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 4, 2019.
13. ^ ^{A b} Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved March 4, 2019.
14. ^ S. Sheppard et al. a .: A Southern Sky and Galactic Plane Survey for Bright Kuiper Belt Objects (PDF) . In: American Astronomical Society Journal . 43, July 26, 2011. arxiv : 1107.5309 . bibcode : 2011DDA .... 42.1007P . doi : 10.1088 / 0004-6256 / 142/4/98 .
15. ↑ M. Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved March 4, 2019.
16. ↑ AstDyS-2: (278361) 2007JJ43 . Universita di Pisa. Retrieved March 4, 2019.
17. ↑ M. Brown : 2007 JJ43 doesn't have a big moon . Twitter. February 3, 2012. Retrieved March 4, 2019.