3. CelestialBody#

class CelestialBody(name: str, mass: ArrayWUnits, mean_radius: ArrayWUnits, grav_param: ArrayWUnits, base_frame: Frame, spice_id: int | str = None, gs_list: list = [])#

Bases: Body

Defines an astronomical body like the Sun, a planet, dwarf planet, moon, asteroid, or comet.

Parameters:

name (str) – The written name of the CelestialBody.
mass (ArrayWUnits) – The mass of the CelestialBody. Recommend expressed in units of kilograms.
mean_radius (ArrayWUnits) – The mean radius of the CelestialBody. Recommend expressed in units of kilometers.
grav_param (ArrayWUnits) – The gravitational parameter of the CelestialBody. Recommend expressed in units of \(\frac{km^3}{s^2}\).
base_frame (Frame) – The body-centered, body-fixed reference frame attached to the CelestialBody.
spice_id (int or str, optional) – The NAIF ID code of the object. May be given as an integer ID or as a string. Defaults to None.
gs_list (list, optional) – A list containing all of the ground stations on the surface of the CelestialBody. Defaults to [].

See also

scarabaeus.Constants: List of Scarabaeus-defined planetary constants.
scarabaeus.Frame: Scarabaeus’ representation of reference frames.

Examples

Create a CelestialBody object with numerical values that are half that of Jupiter, from the Constants library.

# initial setup
import scarabaeus as scb

# get planetary values from Constants
jov_constants = scb.Constants.jupiter

# define the celestial body
half_jupiter = scb.CelestialBody(
    name        = "HALF JUPITER",
    mass        = jov_constants["mass"] / 2,
    mean_radius = jov_constants["radius"] / 2,
    grav_param  = jov_constants["mu"] / 2,
    base_frame  = scb.Frame('IAU_JUPITER')
    spice_id    = 5,
    gs_list     = []
)

>>> jupiter.disp_properties()
                            HALF JUPITER
===================================================================
mass                     : 9.490623355393134e+26 kg
mean_radius              : 35746.0 km
gravitational parameter  : 63343267.460900396 mu
reference frame          : IAU_JUPITER (599 - JUPITER)
SPICE ID                 : -599
attached ground stations : []

Attributes

`base_frame`	The reference frame attached to the CelestialBody.
`grav_param`	The gravitational parameter of the CelestialBody given, by convention, in units of \(\frac{km^3}{s^2}\).
`gs_list`	All GroundStation objects attached to the surface of the CelestialBody.
`mass_profile`	Stored constant or polynomial mass profile.
`mean_radius`	The mean radius of the CelestialBody.
`name`	The name of the Body object.
`spice_id`	The SPICE ID of the Body object.

Methods

`add_ground_station`(gs_to_add)	Adds a new GroundStation object to the list of ground stations attached to the CelestialBody object.
`disp_properties`()	Displays all properties of the CelestialBody object in a readable format.
`fit_mass_profile_from_data`(t_array, m_array, ...)	Fits a polynomial to a mass time history and sets it as the new mass profile.
`from_constants`(cb_name)	Creates a CelestialBody object from a given name using its respective values as defined in Scarabaeus' Constants library.
`get_mass`(t)	Evaluates the time-varying mass profile at specified epochs.
`get_state`(epoch_0[, reference_frame, origin])	Retrieves the state of the body relative to a given origin in a specified reference frame.
`mass`([t])	Returns the mass of the body.
`set_mass_profile`(poly, units)	Sets the mass profile of the body using a polynomial function and associated units.

classmethod from_constants(cb_name: str) → Self#

Creates a CelestialBody object from a given name using its respective values as defined in Scarabaeus’ Constants library.

Parameters:: cb_name (str) – The name of the desired celestial body to create a Scarabaeus CelestialBody object for.
Returns:: cb_out – A CelestialBody object initialized with all relevant values as defined by the given constant value.
Return type:: CelestialBody
Raises:: not_def_err – Raised when the given cb_name does not match an object in Scarabaeus’ constants library.

3. CelestialBody#

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