Data Set Overview
  =================
    OVERVIEW

    This data set is a compilation of published diameters, albedos, and
    densities for Transneptunian Objects (TNOs) and Centaurs.  A total of 190
    objects are listed, many with more than one entry.  This version covers
    published values through 31 March 2016.

    DATA

    Data were collected from the published literature for TNOs and Centaurs,
    with many objects having data reported by more than one group.  Reported
    values for Pluto and Charon are limited to those published after 1985.
    Entries are listed by object permanent number, then by provisional
    designation, then by year of publication, then alphabetically by
    author(s).  Users are referred to the respective papers regarding details
    of observations and methodology.


    TABLES

    The table 'tno_centaur_diam_alb_dens' lists data for objects with the
    following columns:

       * object number, name, and provisional designation;
       * object heliocentric semimajor axis (AU), eccentricity, and
      inclination;
       * object dynamical type;
       * number of known companions;
       * MPC-reported absolute magnitude (as of 31 March 2016);
       * absolute magnitude value used in albedo calculation with error bar;
       * effective diameter (km) with upper/lower error bars and note code;
       * primary diameter (km) with upper/lower error bars and note code;
       * companion diameter (km) with upper/lower error bars and note code;
       * albedo with upper/lower error bars, note code, and color code;
       * system mass density (g/cm^3) with upper/lower error bars and note
      code;
       * methods used for diameter/albedo determination and density
      determination;
       * and reference code.

    Dynamical type codes are as follows:
       1:2 = Neptune 1:2 resonance object,
       2:5 = Neptune 2:5 resonance object,
       2:7 = Neptune 2:7 resonance object,
       3:5 = Neptune 3:5 resonance object,
       3:8 = Neptune 3:8 resonance object,
       3:10 = Neptune 3:10 resonance object,
       4:7 = Neptune 4:7 resonance object,
       CEN = Centaur,
       CUB = Cubewano,
       HAU = Haumea family,
       NL4 = Neptune trojan, L4 position,
       PLU = Plutino (= Neptune 2:3 resonance object),
       SAT = satellite,
       SDO = scattered disk object, and
       TNO = other Transneptunian Object.
    Dynamical types are based on the Minor Planet Center 'Unusual Minor
    Planet' listings and on classifications by the Deep Ecliptic Survey Team
    [http://www.boulder.swri.edu/~buie/kbo/desclass.html] (see Elliot et al.,
    2005).  Haumea family members are those listed by Snodgrass et al., 2010.

    For single objects, effective diameter is the measured diameter and the
    component diameter columns have null values.  For objects with more than
    one component, effective diameter is the combined effective diameter
    (where D_eff^2 = D_1^2 + D_2^2 for binaries, etc.) and individual
    component diameters are provided in the respective columns.  In general,
    albedo and density values are the system averages; if they are specific to
    a component, they include a note code specifying which component (1, 2, 3,
    ...) in a separate entry for that component.  Separate entries are also
    provided for additional components after the first two, again with note
    codes specifying which component (3, 4, ...).

    Note codes indicate comments on data values as follows (more than one code
    may apply):
       1, 2, 3, ... = component diameter for first, second, third, etc.,
      system component;
       A = assumed, applies to adopted values used from other publications or
      to assumed densities used for dynamical determinations of
      diameter/albedo;
       D = derived by the compiler from values reported by the respective
      source;
       G = greater than;
       L = less than;

    Albedo color codes indicate color reported by the source:  B = blue, R =
       red, V = visual, and * = geometric (no color specified).

    Method codes for diameter/albedo determinations are as follows (more than
    one code may apply):
       E = mutual events;
       I = direct imaging;
       M = multiple or modified methods (see respective source for details);
       O = stellar occultation;
       T = thermal/radiometric observations/modeling;
       Y = dynamical (based on system mass from orbit determination, observed
      magnitude, and assumed density;
       # = cited source reported only system mass, values given here are
      derived;
       * = reanalysis of previously published results.

    Method codes for density determinations are as follows (more than one code
    may apply):
       H = hydrodynamic model (based on observed/derived oblateness).
       M = multiple or modified methods (see respective source for details);
       Y = dynamical (based on system mass from orbit determination and
      independently measured diameter);
       * = reanalysis of previously published results.

    Reference codes refer to full reference information listed in the
    'references' table.  This table has columns for reference code and full
    reference.

    Regarding uncertainties on measured values, readers are referred to the
    respective references.  Dashes or invalid inputs (usually -9.99) indicate
    unassigned or unknown values.


    MODIFICATION HISTORY

    Differences between the current database version and the previous version
    (2015) are:

       * A total of 190 objects/systems are represented, or 9 more than the
      previous release.
       * A total of 582 entries are included, or 33 more than the previous
      release.
       * Heliocentric orbit semimajor axis, eccentricity, and inclination are
      updated from the MPC Orbit (MPCORB) Database, and outer solar system
      dynamical types are supplemented by classifications from the Deep
      Ecliptic Survey Team.

    Modifications in successive versions are summarized as follows:
       * V1.0 (31 March 2013) contained 341 entries representing 125 objects/
      systems and included object number, name, and provisional designation;
      heliocentric semimajor axis, eccentricity, inclination, and dynamical
      type; number of known companions; absolute magnitude from MPC and as
      used in albedo calculations; effective diameter and (for binary/
      multiple objects) primary and secondary diameters; albedo, system mass
      density, codes for methods used, and reference codes.
       * V2.0 (31 March 2014) contained 519 entries representing 178 objects/
      systems.
       * V3.0 (31 March 2015) contained 549 entries representing 181 objects/
      systems.
       * V4.0 (31 March 2016) contains 582 entries representing 190 objects/
      systems.


    JOURNALS USED

    Cited sources include articles from the following journals:  Astronomy and
    Astrophysics; Astronomical Journal; Astrophysical Journal; Astrophysical
    Journal Letters; Bulletin of the American Astronomical Society; Earth,
    Moon and Planets; Icarus; Monthly Notices of the Royal Astronomical
    Society; Nature; Publications of the Astronomical Society of the Pacific;
    and Science.  Other sources are from conference proceedings, IAUCs, and
    book contributions.


    REFERENCES

    Elliot, J. L., et al., 2005, The Deep Ecliptic Survey:  A search for
    Kuiper belt objects and Centaurs. II. Dynamical classification, the Kuiper
    belt plane, and the core population, Astron. J., 129:1117-1162.

    Snodgrass, C., B. Carry, C. Dumas, and O. Hainaut, 2010, Characterisation
    of candidate members of (136108) Haumea's family, Astron. & Astrophys.,
    511:A72.

Confidence Level Overview
  =========================
    The Astrophysics Data System (ADS) was used to collect the data presented
    in these tables. Users are referred to the individual papers in the
    ancillary document for the confidence level of each item.