How to do?

SkyBoT . resolver

Solar system objects name resolver

What about Skybot.resolver

Skybot.resolver is a service of the IMCCE's Virtual Observatory project allowing to resolve the name of a Solar System object (asteroid, planet, natural satellite or comet) in celestial coordinates.

This method shall be used only in the framework of the SkyBoT service. For any other need, please, use instead the SsODNet service to resolve the name of any Solar System object.

The service can be used as a Web service and easily integrated into your own software (cf. Skybot.resolver main page). We propose some examples of client programs for that. This page describes how to do with some of the input parameters of the service.

How to use Skybot.resolver service?

Several methods can be helpful:
  • implement yourself the Skybot Web service resolver method in your own software (see client templates) or call the HTTP request on the command line interface using non-interactive file transfert programs such as wget or curl (see the how to consume section).
  • use the Skybot services through a VO-compliant software which implements them, such as Aladin, or other VO applications. For example you can directly submit a request to Skybot.resolver in the Location entry of the File → Load Table menu of Topcat software.

How to select a Sso by its name?

The choice of a Sso can be done by its official name, or its number, or its provisional designation. The knowledge database of SkyBoT does not recognize all the possible designations of Sso. In particular, historical names of asteroids, comets and natural satellites are not recognized, and you must use the current designations of Sso. If needed, use the SsODNet service if you want to resolve any name of Solar System objects.

The nomenclature of Sso names is defined and maintained by the Working Group for Planetary System Nomenclature (WGPSN) of the Division III of the International Astronomical Union.

The general syntaxe of Sso names in SkyBoT is the following:

<prefix>:<name>

where <prefix> is one of the following codes:

  • a to point out an asteroid
  • c to point out a comet
  • dp to point out a dwarf planet
  • p to point out a planet
  • s to point out a natural satellite

and where <name> is the official number or name, or the provisional designation of the Sso. The space character in the provisional designation of asteroids can be substituted by the underscore (_) or the HTML character %20.

Examples:

dp:ceres
a:3834
a:1992_SZ14 
p:mars
s:501
c:1P
c:P/d'Arrest

Restriction: the names of asteroids and comets must be the official names adopted by IAU. If not, they could not be recognized. You can use the SsODNet service to seek for and to resolve solar system object names. For the natural satellites, only the ones for which an ephemeris is available are recognized.

How to define the epoch?

The parameter epoch is used to define the epoch of observation of a field of view, or generally speaking, the epoch for which one wants to know the list of solar system objects located in the given area of the celestial sphere. The epoch must be formatted as an ISO 8601 date (recommended) or as a julian day or as a textual english date (in accordance with the GNU syntax of dates).

Examples of valid dates:

  • now
  • 2006-01-27T1:53:34
  • 2453762.529467592
  • 10 September 2000
  • +1 day
  • +1 week 2 days 4 hours 2 seconds
  • next Thursday
  • last Monday

The epoch must be expressed in the UTC timescale. The period of time covered by SkyBoT is given by the method status.

Restriction: the shortcut 'now' can be used only in the HTTP request, not when calling the Web service.

Tolerance: the character 'T' of the ISO 8601 format can be omitted.

How to define the observer?

— For a terrestrial observer, enter the IAU code of the observatory of your choice, or the code 500 for an observer located at the centre of mass of the Earth (geocenter). If the place of observation is not referenced in the database of IAU observatories, then provide the geographical coordinates formatted as a geographic location URI:
[+-]latitude, [+-]longitude, altitude
or as the less recommended free format:
[+-]longitude [+-]latitude altitude

The longitude and latitude must be expressed in decimal degrees in the WGS84 reference system, and the altitude must be expressed in meters above the mean sea level. Longitudes are negative toward West. The sign + of the longitude and latitude can be omitted. If not, use the encoding %2B instead of the symbol + which is not correctly transmitted in the URL.

Example for Paris observatory (2°20′11.4874" E, 48°50′11.32" N, 67 m): 

-observer=007
-observer=%2B48.836477778, 2.336524278, 67.0

— For an extra-terrestrial observer or an observer onboard a spacecraft, use one of the following codes recognized by SkyBoT:

earth@L2 | 500@L2 | @L2 | L2
for an observer located at the libration point L2 of the system Sun-(Earth+Moon)
@euclid | @-680
for an observer onboard the Euclid spacecraft
@kepler | @-227 | c55
for an observer onboard the Kepler spacecraft
@rosetta | @-226
for an observer onboard the Rosetta spacecraft
@tess | @-95 | c57
for an observer onboard the TESS spacecraft