Skybot.conesearch is a service of the IMCCE's Virtual Observatory project allowing to
search for and identify Solar System objects (planets, major satellites, asteroids and comets) that are present in
a field of view of given celestial coordinates and radius at a given epoch.
The service can be used as a Web service and easily integrated into your own software (cf.
Skybot.conesearch 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.
The ephemerides of planets are, by default, computed with the IMCCE's INPOP
4-D planetary theory. The ephemerides of the natural satellites are computed from various peculiar planetary solutions.
The ephemerides of the asteroids and comets are computed by numerical integration taking into account the perturbation
of the 8 planets, in the framework of the post-newtonian approximation. The dynamical properties of the asteroids are
taken from the ASTORB database of the Lowell Observatory or the
MPCORB database of the Minor Planet Center.
The dynamical properties of the comets are taken from the COMETPRO
database of the IMCCE.
The dynamical properties of asteroids and comets are updated weekly (early Monday morning).
The dynamical properties of the planets and their natural satellites are updated as soon
as a new solution has been made publicly available.
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.
The parameter radius is used to define the size of the requested field of view (FOV) in arcsec.
A single value assumes a circular FOV of the given radius. A value ΔαxΔδ assumes a
rectangular FOV of size Δαcos(δ) in right ascension and Δδ in declination.
Examples:
Restriction:The size of the FOV must not exceed 30°, at risk of a long waiting time of the response.
— 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