(528381) 2008 ST 291

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Asteroid
(528381) 2008 ST 291
Properties of the orbit ( animation )
Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type RKBO 1: 6 or
"Distant Object"
Major semi-axis 99.885  AU
eccentricity 0.576
Perihelion - aphelion 42,305 AU - 157,465 AU
Inclination of the orbit plane 20.8 °
Length of the ascending node 331 °
Argument of the periapsis 324.7 °
Time of passage of the perihelion July 27, 1954
Sidereal period 998 a 3.6 M.
Physical Properties
Medium diameter approx. 549 km
Albedo 0.09
Absolute brightness 4.4 - 4.6 mag
history
Explorer Megan E. Schwamb
Michael E. Brown
David L. Rabinowitz
Date of discovery September 24, 2008
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.

(528381) 2008 ST 291 is a large trans-Neptunian object , which is classified as a resonant KBO (1: 6 – resonance) or more generally as a “distant object” . Because of its size, the asteroid is a dwarf planet candidate .

discovery

2008 ST 291 was discovered on September 24, 2008 by an American team of astronomers consisting of Megan Schwamb, Mike Brown and David Lincoln Rabinowitz at the Palomar Observatory ( California ). The discovery was announced on November 14, 2009.

The asteroid's observation sheet begins with the official discovery observation in September 2008. In December 2018, a total of 85 observations were made over a period of 10 years. The last observation so far was carried out in December 2017 as part of the Pan-STARRS program.

properties

Orbit

The orbit of 2008 ST 291 (blue) compared to Pluto and the planets.

2008 ST 291 orbits the sun in 998.30 years on a highly elliptical orbit between 42.31  AU and 157.47 AU from its center. The orbit eccentricity is 0.576, the orbit is inclined 20.76 ° to the ecliptic . The planetoid is currently 61.13 AU from the sun and 61.60 AU from the earth . He passed through perihelion for the last time in 1954, so the next perihelion is not likely to take place until 2952. (As of February 3, 2019)

Marc Buie ( DES ) classifies the planetoid as RKBO ( 1: 6 resonance with Neptune ); the Minor Planet Center lists it as a “Distant Object” .

size

Currently, a diameter of about 549 km is assumed, based on a reflectivity of 9% and an absolute brightness of 4.6  m ; However, this is fraught with uncertainties, as the estimates range from 370 to 820 km due to the still unknown albedo. The apparent magnitude of 2008 ST 291 is 22.29  m .

Since it can be assumed that 2008 ST 291 is in hydrostatic equilibrium due to its size and therefore has to be largely round, it should meet the criteria for classification as a dwarf planet . Mike Brown assumes that 2008 ST 291 is likely a dwarf planet.

Provisions of the diameter for 2008 ST 291
year Dimensions km source
2018 640.0 Johnston
2018 549.0 Brown
The most precise determination is marked in bold .

See also

Web links

Individual evidence

  1. ^ A b Marc W. Buie : Orbit Fit and Astrometric record for 08ST291 . SwRI (Space Science Department). Archived from the original on August 18, 2010. Retrieved February 3, 2019.
  2. ↑ a b c (528381) 2008 ST291 at the IAU Minor Planet Center (English)
  3. ↑ MPC : MPEC 2009-V68: 2008 ST291 . IAU . November 14, 2009. Retrieved February 3, 2019.
  4. ↑ (528381) 2008 ST291 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved February 3, 2019. Template: JPL Small-Body Database Browser / Maintenance / Alt
  5. ↑ (528381) 2008 ST291 in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
  6. ↑ a b Mike Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved February 3, 2019.
  7. ^ Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved February 3, 2019.