Target Names

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Introduction

Names for small bodies are tricky. Many minor planets have multiple designations, and it is common for new names to be added or existing names changed or modified sometimes long after they were initially assigned. There are also numerous name collisions between small bodies of various types - there are comets that share names with asteroids, asteroids with the same name as meteorites, and planetary moons with the same names as asteroids. So when identifying observational targets in your PDS data products, it is vitally important that the target be uniquely identified by the <name> in its <Target_Identification> class.

Unambiguous Identification

The make sure a target object is uniquely identified, you should formulate the <name> value so that the following is true:

  1. The name string contains at least one identifier that can only be associated with a single physical object.
  2. The name string contains at least two different identifiers for each object wherever possible.

The first rule ensures that there is only a single object that could possibly be intended; the second provides a cross-check on that identification, in case the identity of the target object is questioned. To help with parsing name strings for use in database searches, the SBN has developed the following style sheet for formulating target names. You must use this format for all target names in products archived with the Small Bodies Node.

If you have any questions about the correct name string to use, please contact the Small Bodies Node and we will happily convert whatever ID you have to a unique name string for your labels.

SBN Target Name Strings

Following are the rules for formulating values of the <name> attribute in your <Target_Identification> classes for any and all data coming in to the SBN archives. Unless otherwise stated, SBN follows the formatting conventions used by the organizations responsible for assigning names and designations to these objects - the International Astronomical Union (IAU) or its designated deputy. For definitions of the various name and identification types mentioned below, see Solar System Object Names elsewhere on this wiki.

Note that case is significant in object identifications. The correct case should always be used in provisional and discovery designations as well as names.

Major Planets

Format: Name

For the eight major planets (and the sun), the name string is just the properly capitalized English name - so "Jupiter", not "JUPITER" or "jupiter".

Examples:

  • Earth
  • Jupiter
  • Sun

Dwarf Planets

Format: (minor_planet_number) Name

Dwarf planets should be identified by Minor Planet Number in parentheses followed by their properly capitalized English name.

Examples:

  • (1) Ceres
  • (134340) Pluto
  • (136199) Eris

Asteroids

Formats:

1. (minor_planet_number) Name
2. (minor_planet_number) principal_provisional_designation
3. principal_provisional_designation (provisional_designation)
4. provisional_designation

Use format #1 when the asteroid has both a minor planet number and a name. The number comes first and is enclosed in parentheses.

Use format #2 for asteroids that have a minor planet number, but have not yet been officially named. Asteroids with more than one provisional designation will have one of those designations indicated as the principal one. If an asteroid has only one provisional designation, it is considered the principal provisional designation for name string creation purposes.

Use format #3 if the asteroid has not yet received a minor planet number, referencing it by its principal provisional designation and providing one other provisional designation as a cross-reference.

Use format #4 for those cases where the target is an asteroid that has only a single provisional designation attached to it. This is likely to be rare in archival data.

Examples:

  1. (2309) Mr. Spock
  2. (12528) 1998 KL31
  3. 2015 AQ230 (2010 GS119)
  4. 2015 AA23

Comets

Comet name strings are fairly complex an not easy to summarize in a simple format statement, so instead we'll list the constituent pieces in the order they are used:

1. Periodic Comet Number Omit this element if the comet does not have a periodic number assigned.
2. Comet Type Letter All comets have a designated type, which will be one of these letters followed by a slash ('/'):
P    Periodic comet
C    Non-periodic (or very long period) comet
X    Comet with an undeterminable orbit
D    Comet that is known to be destroyed or has disappeared

Note that the comet type may change for some objects as time passes. On occasion even D/ comets have reappeared.

3. Principal Discovery Designation This may be a comet designation, or for comets that looked like asteroids on first discovery, it might be an asteroid provisional designation. In either event, when there are multiple provisional or discovery designations associated with a single comet, the Minor Planet Center will designate which of the designations is considered the principal one. That is the designation that should be used here.
4. (Name) The name assigned to this object, enclosed in parentheses. For comets this name can change, sometimes retrospectively, as objects thought lost are recovered, or things that originally looked like asteroids start behaving like comets. Comet names are not required to be unique, and there are many comets that share a name and must be differentiated by their principal discovery designations.

Note: Because of the common duplication of comet names and the significance of periodic comets, which can be observed over multiple apparitions, the SBN adds a serial number to the end of comet names for all periodic (P/ type) comets to aid in distinguishing them.

Examples:

  • 1P/1682 Q1 (Halley 1)
  • D/1993 F2 (Shoemaker-Levy 9)
  • C/2014 XB8 (PANSTARRS)
  • C/2014 Q2 (Lovejoy)

Dual-Nature Objects

For objects that have been recognized as dual-nature - acting like comets for part of their orbit, and asteroids the rest of the time - use the name string form that is appropriate to the data collection. So, for example, if the dual-nature object Chiron is being observed for as asteroidal properties, it should be identified as "(2060) Chiron". If is being observed for its cometary behviour, it should be identified as "95P/1977UB (Chiron)".

Note: Periodic comets that retain their asteroid name when they are found to have cometary behaviour will not have serial numbers appended to their names.

Natural Satellites

Provisional Designation

Format: S/yyyy primary_body serial_number

All provisional designations for natural satellites begin with the letter S followed by a slash ('/') - similar to the comet type designator. This if followed by the year of discovery, and then by an indication of the primary body the satellite is orbiting. For major planets, these one-letter abbreviations are used:

H    Mercury
V    Venus
E    Earth
M    Mars
J    Jupiter
S    Saturn
U    Uranus
N    Neptune

For satellites of dwarf planets and asteroids identify the primary body by including the best available unique identifier - the asteroid number where there is one, or the principal provisional designation for unnumbered asteroids, in parentheses.

The primary body identifier is them followed by a serial number based on the order of discovery in the given year.

Examples:

  • S/2007 S1 - The first new Saturnian satellite discovered in 2007
  • S/1993 (243) 1 - The first new satellite of asteroid (243) Ida discovered in 1993

Permanent Designation

Once the satellite discovery is confirmed, the satellite is typically given a name along with its permanent designation. Moon names can collide with names of other types of small bodies, so even in this case it is important to include at least two identifiers in the satellite name string.

Format: primary_body roman_numeral (Name)

The primary body should be identified by its name string as described above. The roman numeral is a sequence number assigned in the order that the satellites were named; and finally comes the satellite's own name, in parentheses.

Examples:

  • Uranus XVII (Sycorax)
  • (134340) Pluto IV (Kerberos)
  • (243) Ida I (Dactyl)