List of plutoid candidates

List of plutoid candidates

At present, the International Astronomical Union classifies four objects as plutoids:dubious dp|Pluto, dp|Eris, dp|Haumea, and dp|Makemake; dozens of others are thought likely to be plutoids. The qualifying feature is that plutoids must "have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical shape)."citenews|publisher=International Astronomical Union|title=IAU 2006 General Assembly: Result of the IAU Resolution votes|url=|year=2006|accessdate=2008-01-26] [citeweb|url=|title=Dwarf Planets|publisher=NASA|accessdate=2008-01-22] cite press release|url=|title=Plutoid chosen as name for Solar System objects like Pluto] Except for Pluto, observations are insufficient for direct classification. However, based on present knowledge of how icy bodies gravitationally relax into equilibrium shapes, there are a significant number of potential candidates amongst the population of trans-Neptunian objects (TNOs).citeweb|url=|author=Mike Brown|title=The Dwarf Planets|accessdate=2008-01-20] There are about 70 candidates now, but it is possible that this number will increase to 2000.

Changes to IAU naming procedures

The IAU has modified its nomenclature procedures such that objects considered highly likely to be plutoids receive differing treatment when receiving names than other TNOs. Objects that have an absolute magnitude less than +1 (and hence a mathematically-delimited minimum diameter of 838 kmcite web
title=Conversion of Absolute Magnitude to Diameter for Minor Planets
publisher=Department of Physics & Astronomy (Stephen F. Austin State University)
author=Dan Bruton
] ) will be overseen by two rather than one naming committee. This procedural decision has no direct bearing on the object's formal classification as a plutoid, but once so named, they are for all practical purposes accepted as such. Makemake and Haumea are the only TNOs to have proceeded through the naming process as presumed plutoids.

Plutoid candidates

Mike Brown estimates that at a diameter somewhere between 200 and 400 km, an icy body relaxes into hydrostatic equilibrium. Following is a list of TNOs that Brown thinks likely qualify as dwarf planets since he estimates they have diameters of at least 400km. However, diameter estimates vary widely, and they are therefore ordered here by their absolute magnitudes, "H," rather than diameter. Theoretical minimum diameters correspond to a maximum albedo of 1. Although many TNOs are thought to be dark, and therefore substantially larger than this lower limit, Eris has a high albedo of 0.8–0.9, and the Haumea family are also thought to be bright. (See albedo.)

With diameters above 900km

These TNOs are at least 900 km across in Brown's estimation.


External links

* [ Which are the Dwarfs in the Solar System?] Tancredi,G; Favre,S. Icarus, Volume 195, Issue 2, p. 851-862.

ee also

* List of trans-Neptunian objects

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • List of minor planets — Objects in the Solar System By orbit By size By discovery date …   Wikipedia

  • List of asteroids — This is a list of numbered minor planets in sequential order.As of|2008|9|url= there are 192,280 numbered minor planets, and many more not yet numbered. Five minor planets have also been… …   Wikipedia

  • List of dwarf planet candidates — At present, the International Astronomical Union classifies five objects as dwarf planets: Ceres, Pluto, Eris, Haumea, and Makemake, though dozens of others are thought likely to be classified as such in the future. The qualifying feature of… …   Wikipedia

  • List of gravitationally rounded objects of the Solar System — Objects in the Solar System By orbit By size By discovery date …   Wikipedia

  • Plutoid — A plutoid is a trans Neptunian dwarf planet or an object that is likely to be such a body and that has received a permanent name as a plutoid. The International Astronomical Union (IAU) developed this category of astronomical objects as a… …   Wikipedia

  • Oort cloud — An artist s rendering of the Oort cloud and the Kuiper belt (inset). Sizes of individual objects have been exaggerated for visibility …   Wikipedia

  • Kuiper belt — Known objects in the Kuiper belt, derived from data from the Minor Planet Center. Obje …   Wikipedia

  • Scattered disc — The scattered disc (or scattered disk) is a distant region of the Solar System that is sparsely populated by icy minor planets known as scattered disc objects (SDOs); a subset of the broader family of trans Neptunian objects (TNOs). The scattered …   Wikipedia

  • Haumea family — The Haumea family is the only identified Trans Neptunian collisional family; that is, the only group of TNOs with similar orbital parameters and physical characteristics that suggest they originated in the disruptive impact of a progenitor… …   Wikipedia

  • Makemake (dwarf planet) — Makemake Makemake as seen by the Hubble Space Telescope Discovery Discovered by …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”