(444030) 2004 NT ₃₃

Asteroid (444030) 2004 NT 33
Properties of the orbit ( animation ) Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type	CKBO  ( «Hot» )  or DO (E SDO ), «Distant Object»
Major semi-axis	43.648  AU
eccentricity	0.155
Perihelion - aphelion	36.896 AU - 50.4 AU
Inclination of the orbit plane	31.2 °
Length of the ascending node	240.9 °
Argument of the periapsis	38.7 °
Time of passage of the perihelion	April 17, 1985
Sidereal period	288 a 4.4 M
Mean orbital velocity	4.471 km / s
Physical Properties
Medium diameter	${\displaystyle 423_{-80}^{+87}\mathrm {km} }$
Albedo	${\displaystyle 0{,}125_{-0,039}^{+0,069}\mathrm {} }$
Rotation period	7.87 ± 0.05 h (0.328 d )
Absolute brightness	4.74 ± 0.11 mag
Spectral class	C.
history
Explorer	Michael E. Brown , Chadwick A. Trujillo , David L. Rabinowitz
Date of discovery	July 13, 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.

(444030) 2004 NT ₃₃ is a large trans-Neptunian object in the Kuiper belt , which is classified as a Cubewano (CKBO) or an extended Scattered Disk Object (DO) in terms of orbital dynamics . Because of its size, the asteroid is a dwarf planet candidate .

discovery

2004 NT ₃₃ was developed on July 13, 2004 by a team of astronomers consisting of Mike Brown ( CalTech ), Chad Trujillo ( Gemini Observatory ) and Dave Rabinowitz ( Yale University ), as part of the Near Earth Asteroid Tracking Project ( NEAT) discovered at the 1.2 m Oschin Schmidt telescope of the Palomar Observatory ( California ). The discovery was announced on September 1, 2007 together with 2003 UY ₄₁₃ , 2003 UZ ₄₁₃ , 2005 CA ₇₉ , 2005 CB ₇₉ and 2005 UQ ₅₁₃ , the planetoid was later given the minor planet number 444030 by the IAU .

After its discovery, NT _{33 could be identified} on photos taken as part of the Digitized Sky Survey (DSS) program at the Siding Spring Observatory in 2004 and thus extended its observation period by 22 years in order to calculate its orbit more precisely. In August 2018, there were a total of 39 observations over a period of 36 years. The last observation so far was made in August 2018 at the Purple Mountain Observatory . (As of March 7, 2019)

properties

Orbit

2004 NT ₃₃ orbits the sun in 288.37 years on a slightly elliptical orbit between 34.83  AU and 51.84 AU from its center. The orbital eccentricity is 0.155, the orbit is 31.23 ° inclined to the ecliptic . Currently, the planetoid is 39.22 AU from the Sun. He last passed through perihelion in 1985, so the next perihelion should take place in 2273.

Marc Buie ( DES ) classifies the planetoid as an extended SDO (ESDO or DO ), while the Minor Planet Center him as Cubewano classifies, where he ground dynamically to the "hot" classical KBO heard; the latter also lists it as a non-SDO and generally as a “distant object” .

Size and rotation

A diameter of 423 km is currently assumed, based on a reflectivity of 7% and an absolute brightness of 5.1  ^m . Assuming a diameter of 423 km, this results in a total surface of around 562,000 km ² . The apparent magnitude of 2004 NT ₃₃ is 21.01  ^m .

Since it can be assumed that 2004 NT ₃₃ is in hydrostatic equilibrium due to its size and therefore must be largely round, it should meet the criteria for classification as a dwarf planet . Mike Brown believes that 2004 NT ₃₃ may be a dwarf planet. Gonzalo Tancredi did not make a recommendation in 2010.

Using light curve observations carried out in 2009 at the Galileo (TNG) and the Sierra Nevada Observatory (OSN) ( La Palma and Granada , Spain ), 2004 NT ₃₃ rotates once around its axis in 7 hours and 52.2 minutes. This means that in a 2004 NT ₃₃ year it performs 321203.5 self- rotations (“days”). Since the observation time at that time was insufficient, the result could also be completely wrong.

Determinations of the diameter for 2004 NT ₃₃

year	Dimensions km	source
2010	554.0	Tancredi
2012	460.81	LightCurve DataBase
2014	423.0 +87.0−80.0	Vilenius et al. a.
2018	490.0	Brown
The most precise determination is marked in bold .

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

• Precovery photos from 2004 NT ₃₃
• 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} MPC : MPEC 2010-S44: Distant Minor Planets (2010 OCT.11.0 TT) . IAU . September 25, 2010. Retrieved March 7, 2019.
2. ↑ E. Lellouch et al. a .: "TNOs are Cool": A survey of the trans-Neptunian region. IX. Thermal properties of Kuiper belt objects and Centaurs from combined Herschel and Spitzer observations (PDF) . In: Astronomy and Astrophysics . 557, No. A60, June 10, 2013, p. 19. bibcode : 2013A & A ... 557A..60L . doi : 10.1051 / 0004-6361 / 201322047 .
3. ^ ^{A b} Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved March 7, 2019.
4. ^ ^{A b} Marc W. Buie : Orbit Fit and Astrometric record for 444030 . SwRI (Space Science Department). Retrieved March 7, 2019.
5. ↑ ^{a b c} (444030) 2004 NT33 at the IAU Minor Planet Center (English) Accessed March 7, 2019.
6. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
7. ↑ ^{a b c d} 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 .
8. ↑ 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 .
9. ↑ ^{a b} LCDB Data for (444030) 2004 NT33 . MinorPlanetInfo. 2012. Retrieved March 7, 2019.
10. ↑ MPC : MPEC 2007-R02: 2003 UY413, 2003 UZ413, 2004 NT33, 2005 CA79, 2005 CB79, 2005 UQ513 . IAU . September 1, 2007. Accessed March 7, 2019.
11. ↑ MPC : MPC / MPO / MPS Archive . IAU . Retrieved March 7, 2019.
12. ↑ (444030) 2004 NT33 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 7, 2019.
13. ↑ MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 7, 2019.
14. ↑ (444030) 2004 NT33 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 7, 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 7, 2019.