• MPC Preparation (Info)

  • Explanation of References on Astrometric Observations

    Astrometric observations of comets, minor planets and natural satellites that are accepted for publication in the Minor Planet Circulars (MPCs), the Minor Planet Supplement (MPSs), the Minor Planet Electronic Circulars and the IAU Circulars have a publication reference copied onto the observational record.

    In the new observation format this reference is easily readable, but limitations in the current format mean that the reference has to be compressed. It is this compressed format that is described here. The information should be sufficient to allow one to convert from the compressed format to a readable format.

    The compressed reference is stored in columns 73-77 of the observation record. For the purpose of this description, column 73 of the observation record will be referred to as column 1 of the designation. Similarly, column 77 of the observational record is column 5 of the designation.

    1: Temporary References on MPECs

    Observations that appear on MPECs have in the past had an implicit reference: the circular upon which they appeared. Since observations from these circulars were often being used in the general community without attribution, an explicit reference is now added to the observations on the circular. This is a temporary reference and is replaced by a permanent reference when the observations appear in the MPCs or MPSs.
     Col.   Purpose
      1     "E"
      2     Half-month of MPEC preparation
     3-5    Circular number within the half-month.
    Example: observations appearing on MPEC 2004-P03 have the reference "EP003". Note that there is no need to store the year in the temporary designation, as acceptable observations will acquire a permanent reference upon publication in the MPCs and MPSs.

    2: Permanent References

    Permanent references refer to the MPCs and MPSs, as well as other journals. It is expected that users of observational data, where appropriate (and this would probably apply to all uses of the data on the web), refer explicitly to the publication source for each observation.

    A: Five Digit References

    Five-digit references refer to publication in the MPCs.
     Col.   Purpose
     1-5    MPC number
    Example: "24133" refers to "MPC 24133".

    B: "@" + Four Digit References

    Five-digit references refer to publication in the MPCs with numbers above 99999.
     Col.   Purpose
     1      "@"
     2-5    MPC number excess over 100000
    Example: "@0133" refers to "MPC 100133".

    C: "#" + Four Characters

    Five-digit references refer to publication in the MPCs with numbers above 109999.
     Col.   Purpose
      1     "#"
     2-5    Base-62 encoded value of (MPC number - 110000)
    The Base-62 encoding uses the characters "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" to represent "digits" 0 through 61.

    Example: "#002B" = MPC 110135.

    D: Lower-case Letter + Four Digit references

    These references refer to publication in the MPSs.
     Col.   Purpose
      1     Encoded value of (MPS number) DIV 10000
     2-5    (MPS number) MOD 10000
    The value in column 1 is encoded by converting the MPS number to a lower-case letter as follows: CHAR(97+INT(MPS_Number/10000)). Therefore, "a" is used for MPS 1-9999, "b" for MPS 10000-19999, etc.

    Examples: "j8391" refers to "MPS 98391", "a0320" refers to "MPS 320" and "k0001" refers to "MPS 100001".

    E: Tilde + Four Base-62 Character references

    These references refer to publication in the MPSs.
     Col.   Purpose
      1     "~"
     2-5    Base-62 encoded value of (MPS number - 260000)
    The Base-62 encoding uses the characters "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" to represent "digits" 0 through 61.

    Examples: "~0000" refers to "MPS 260000" and "~007M" is "MPS 260456" (since "007M" = 0*62*62*62 + 0*62*62 + 7*62 + 22 = 456).

    F: Upper-case Letter + Four Digit References

    This form of the reference covers a number of journals. The first column indicates which journal, columns 2-5 indicate on which circular in that series the observations appeared.
     Col.   Purpose
      1     Journal identifier
     2-5    Circular number
    Journal identifier
       H    Harvard Announcement Card (HAC)
       I    IAU Circular (IAUC)
       M    Minor Planet Circulars (MPC)
       R    Planetenzirkular des Astronomischen Rechen-Institut (RI)
    Examples: "R0034" refers to "RI 34", "I2340" refers to "IAUC 2340".

    G: Two or More Letters References

    This form of the reference covers most non-MPC journals. The journal identifier takes from two to five characters. If digits appear, these generally refer either to the volume or the circular number in which the observations were published.
    Journal identifier
    AA    V  Astronomy and Astrophysics
    AB    C  Bulletin des Astrophysikalischen Observatoriums Abastumani
    AC    C  Astronomisches Zirkular der Akademie der Wissenschaften der UdSSR
    AE    V  Astronomical Papers prepared for the use of the American Ephemeris and Nautical Almanac
    AJ    V  Astronomical Journal
    AN    V  Astronomische Nachrichten
    AP    V  Astrophysical Journal Supplement
    APO   V  Annales de l'Observatoire de Paris: Observations
    AS    V  Acta Astronomica Sinica
    AZ    V  Astronomicheskij Zhurnal
    AcA   V  Acta Astronomica
    As    V  Astronomy and Astrophysics Supplement
    BA    V  Bulletin Astronomique
    BB    V  Bulletin Astronomique de l'Observatoire Royal de Belgique, Uccle
    BC    V  Bulletin of the Astronomical Institutes of Czechoslovakia
    BG    V  Bulletin de l'Observatoire Astronomique de Beograd
    BN    I  Bulletin of the Astronomical Institutes of the Netherlands
    BP    V  Bulletin de la Societe des amis des sciences et des lettres de Poznan
    BZ    V  Beobachtungs-Zirkulare der Astronomischen Nachrichten
    CB    I  Comet Bulletin of the Orient Astronomical Association
    CC    V  Observatorio Astronomico de Cordoba, Serie Contribuciones
    CD    I  Tsirkulyari Rasadkhonai Stalinobod
    CK    V  Izvestiya Krymskoj Astrofizicheskoj Observatorii
    CM    V  Circulaire de l'Observatoire de Marseille
    CMC   V  Carlsberg Meridian Circle Publications
    CO    V  Odesskij Gosudarstvennyj Universitet Izvestiya Astronomicheskoj Observattorii
    CR    V  Comptes Rendus hebdomadaires de l'academie des sciences de Paris
    CS    V  Soobshcheniya Gosudarstvennogo Astronomicheskogo Instituta imeni P. K. Shternberga
    GOxxx Y  Greenwich Observations for the year 1xxx
    HA    V  Harvard Annal
    HD    V  Veröffentlichungen der Landessternwarte Heidelberg
    HTCDR    Hipparcos-Tycho CD-ROM
    IHW   D  International Halley Watch CD-ROM
    Ic    V  Icarus
    JB    V  Journal of the British Astronomial Association
    JC    C  Japan Astronomical Study Association Circular
    JO    V  Journal des Observateurs
    KB    V  Bulletin of the Kwasan Observatory, Kyoto
    KK    C  Kiev Komet Tsirkular
    LB    C  Lick Observatory Bulletin
    LO    C  Lowell Observatory Bulletin
    LP    V  Publicaciones Observatorio Astronomico de La Plata
    MN    V  Monthly Notices
    NA    V  Annales de l'Observatoire de Nice
    NC    C  Nihondaira Observatory Circular
    NO    V  Publications of the U.S. Naval Observatory, Second Series
    NZ    C  Nachrichtenblatt der Astronomischen Zentralstelle
    OB    V  The Observatory
    PA    V  Publicaations of the Astronomical Society of the Pacific
    PC    C  Poulkovo Observatory Circular
    PD    V  Tartu Astronoonmia Observatooriumi Publikatsioonid
    PK    V  Pyublikatsii Kievskoj Astronomicheskoj Observatorii
    PO    I  Perth Observatory Communication
    PP    I  Izvestiya Glavnoj Astronomicheskoj Observatorii v Pulkove
    PT    V  Pubblicazioni del Osservatorio di Torino
    PZ    C  Zirkular des Astronomischen Hauptobservatoriums Pulkowo
    RA    V  Ricerche Astronomiche
    RM    V  Memoirs of the Royal Astronomical Society
    SA    V  Monthly Notices of the Astronomical Society of Southern Africa
    SOB   V  Observatory Bulletin
    TB    V  Tokyo Astronomical Bulletin
    TC    C  Transval Observatory Circular
    TI    V  Astronomia-Optika Institucio, Universitato de Turku, Informo
    UC    C  Circular of the Union Observatory, Johannesburg
    WO    V  Astronomical Observations of the U.S. Naval Observatory, Washington
    WiA   V  Annalen der Sternwarte der Universitäts Wien
    pM    V  Mitteilungen der Nikolai-Hauptsternwarte zu Pulkowo
    where the second column is "V" for volume numbers, "C" for circular numbers, "I" for issue number, "D" for CD-ROM numbers and "Y" for years.

    Examples: "AN080" refers to "AN 80", "MN008" refers to "MN 8".