(35671) 1998 SN ₁₆₅

Asteroid (35671) 1998 SN 165
Properties of the orbit ( animation ) Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type	CKBO  ( "Cold" ) "Distant Object"
Major semi-axis	37.821  AU
eccentricity	0.04
Perihelion - aphelion	36,309 AU - 39,334 AU
Inclination of the orbit plane	4.6 °
Length of the ascending node	192.1 °
Argument of the periapsis	265.7 °
Time of passage of the perihelion	April 12, 2064
Sidereal period	232 a 7.2 M
Mean orbital velocity	4.804 km / s
Physical Properties
Medium diameter	${\displaystyle 393_{-48}^{+49}\,\mathrm {km} }$
Albedo	${\displaystyle 0{,}060_{-0,013}^{+0,019}\mathrm {} }$
Rotation period	8.84 h (0.368 d )
Absolute brightness	5.707 ± 0.085 mag
Spectral class	C B-V = 0.710 ± 0.060 VR = 0.420 ± 0.030 VI = 0.820 ± 0.010 BR = 1.123 ± 0.082
history
Explorer	Arianna E. Gleason
Date of discovery	September 23, 1998
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.

(35671) 1998 SN ₁₆₅ is a large trans-Neptunian object in the Kuiper belt , which is classified as Cubewano (CKBO) in terms of orbit dynamics . Due to its size, the asteroid may be one of the dwarf planet candidates .

discovery

1998 SN ₁₆₅ was discovered on September 23, 1998 by Arianna Gleason at the 0.9 m telescope of the Kitt Peak Observatory at Steward Observatory ( Arizona ). The discovery was announced on 10 July 1999 the asteroid was on 5 December 2006 by the IAU , the Minor Planet -number 35671 .

After its discovery, in 1998 SN _{165 could be identified} on photos up to September 15, 1998, which were also taken at the Steward Observatory, and thus its observation period was extended by eight days in order to calculate its orbit more precisely. Since then, the asteroid has been observed through various telescopes such as the Herschel Space Telescope and Earth-based telescopes. In October 2018, a total of 230 observations over a period of 66 years were available. The last observation so far was carried out in September 2017 at the Pan-STARRS telescope (PS1) ( Maui ). (As of March 11, 2019)

properties

Animated orbit simulation from 1998 SN ₁₆₅ .

Orbit

1998 SN ₁₆₅ orbits the sun in 232.60 years in an almost circular orbit between 36.31  AU and 39.33 AU from its center. The orbit eccentricity is 0.040, the orbit is 4.61 ° inclined to the ecliptic . The planetoid is currently 39.30 AU from the sun. He will next pass perihelion in 2064, so the last perihelion should have occurred in 1831.

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, it classifies it as a non-SDO and generally as a “distant object” .

Size and rotation

A diameter of 393 km is currently assumed, based on a reflectivity of 6% and an absolute brightness of 5.71  ^m , which was determined using data from the Herschel space telescope. Assuming a diameter of 393 km, this results in a total surface of around 485,000 km². The apparent magnitude of 1998 SN ₁₆₅ is 21.58  ^m .

Since it is conceivable that in 1998 SN ₁₆₅ 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 1998 SN ₁₆₅ to perhaps is a dwarf planet.

On the basis of light curve observations , 1998 SN ₁₆₅ rotates once around its axis in 8 hours and 50.4 minutes. It follows that in a 1998 SN ₁₆₅ year it performs 230656 self- rotations ("days"). However, this is still fraught with uncertainties, as the observation time at that time was insufficient and the error rate is around 30%.

Provisions of the diameter for 1998 SN ₁₆₅

year	Dimensions km	source
2008	460.0 + 060.0- 080.0	Stansberry et al. a.
2013	446.0	Mommert et al. a.
2014	393.0 +48.0−48.0	Vilenius et al. a.
2015	333.83	LightCurve DataBase
2018	393.0	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

• 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 35671 . SwRI (Space Science Department). Retrieved March 11, 2019.
2. ^ ^{A b} Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved March 11, 2019.
3. ↑ ^{a b c} (35671) 1998 SN165 at the IAU Minor Planet Center (English) Retrieved March 11, 2019.
4. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
5. ↑ ^{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 .
6. ^ P. Lacerda, J. Luu : Analysis of the Rotational Properties of Kuiper Belt Objects (PDF) . In: The Astronomical Journal . 131, No. 4, April 2006, pp. 2314-2326. arxiv : astro-ph / 0601257 . bibcode : 2006AJ .... 131.2314L . doi : 10.1086 / 501047 .
7. ↑ ^{a b} LCDB Data for (35671) 1998SN165 . MinorPlanetInfo. 2015. Accessed March 11, 2019.
8. ↑ ^{a b c} I. Belskaya et al. a .: Updated taxonomy of trans-neptunian objects and centaurs: Influence of albedo . In: Icarus . 250, April 2015, pp. 482-491. bibcode : 2015Icar..250..482B . doi : 10.1016 / j.icarus.2014.12.004 .
9. ↑ N. Peixinho et al. 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 .
10. ↑ MPC : MPEC 1999-N17: 1998 SN165 . IAU . July 10, 1999. Retrieved March 11, 2019.
11. ↑ MPC : MPC / MPO / MPS Archive . IAU . Retrieved March 11, 2019. Reference there: MPC 58201 (PDF)
12. ↑ (35671) 1998 SN165 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 11, 2019.
13. ↑ MPC : MPEC 2010-S44: Distant Minor Planets (2010 OCT.11.0 TT) . IAU . September 25, 2010. Accessed March 11, 2019.
14. ↑ MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 11, 2019.
15. ↑ (35671) 1998 SN165 in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
16. ↑ ^{a b} Mike Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved March 11, 2019.
17. ↑ J. Stansberry et al. a .: Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope (PDF) . In: University of Arizona Press . 592, No. 161-179, February 20, 2007. arxiv : astro-ph / 0702538 . bibcode : 2008ssbn.book..161S .
18. ↑ M. Mommert et al. a .: Remnant planetesimals and their collisional fragments: Physical characterization from thermal-infrared observations . September 23, 2013. Accessed March 11, 2019.