ATK.Models.Target

class ATK.Models.Target

Bases: object

Attributes

correction	Degree of proper motion correction that the Target can support.
identifier	Unique identifier from a supported astrometric backend survey (if provided, otherwise None).
radius	Radius of search in which the Target is being utilised.
survey	Survey from which identifier originates (if one was provided, otherwise None).
initial_coords	Initial (i.e. uncorrected) coordinates of target source.
coords	Coordinates of target source, corrected for proper motion.

Methods

from_coord(position)	Construct a Target from a position on the sky.
from_id(id[, survey])	Construct a Target using a unique identifier from a supported astrometric backend survey.
show([show_types, show_all])	Prints structure to stdout in a human-readable format.

Attribute Descriptions

correction: str = 'none'

Degree of proper motion correction that the Target can support.

• 'full' = complete 3-dimensional projection on the sky.

• 'partial' = 2-dimensional plane projection.

• 'none' = no correction.

identifier: int | None = None

Unique identifier from a supported astrometric backend survey (if provided, otherwise None).

(e.g. a Gaia Source ID).

radius: Quantity | None = None

Radius of search in which the Target is being utilised.

survey: str | None = None

Survey from which identifier originates (if one was provided, otherwise None).

initial_coords: SkyCoord

Initial (i.e. uncorrected) coordinates of target source.

If an identifier is provided, a SkyCoord is generated in the frame and epoch of the chosen astrometric backend survey. Otherwise the input SkyCoord is used directly.

coords: SkyCoord

Coordinates of target source, corrected for proper motion. Updated with each stage of astrometric correction.

Method Descriptions

classmethod from_coord(position: SkyCoord)

Construct a Target from a position on the sky.

The provided SkyCoord is transformed to the ICRS frame and used to initialise the target. If no observation epoch is defined (obstime), an epoch of J2000 is assumed.

Astrometric correction (i.e. propagation between epochs) is only possible if the input coordinate includes proper motion information (and optionally distance). If these are not provided, no correction can be applied.

Parameters:

positionSkyCoord

Input sky coordinate defining the target position. May optionally include proper motion and distance information.

Returns:

Self

classmethod from_id(id: int, survey='gaia')

Construct a Target using a unique identifier from a supported astrometric backend survey.

The resulting Target is initialised using the coordinate frame and reference epoch of the selected survey. All astrometric parameters (e.g. position and proper motion) are retrieved from the survey’s VizieR catalogue.

Parameters:

id: int

Unique source identifier from a supported astrometric backend survey.

E.g. a Gaia DR3 Source ID

survey: {‘gaia’}, optional

Survey to use as an astrometric backend.

Currently only Gaia DR3 (gaia) is supported.

Returns:

Self

show(show_types=False, show_all=False)

Prints structure to stdout in a human-readable format.

Parameters:

show_typesbool, optional

If True, print data types of structure attributes.

Default is False

show_allbool, optional

If True, do not truncate printing of large iterables.

Default is False.

Returns:

self