Star catalogs (ctapointing.catalog)

The ctapointing.catalog module provides access to astrometric information from the bright star and GAIA catalogs. In particular, it provides functionality to obtain a list of stars within a certain angular distance to a given ICRS position, with proper magnitude limits.

API

ctapointing.catalog Package

class ctapointing.catalog.BrightStarCatalog(create_from_database=False, filename='bright_star_catalog', min_mag=-12.0, max_mag=3.0)

Yale Bright Star Catalog. Source: http://vizier.u-strasbg.fr/viz-bin/VizieR-3?-source=V/50/catalog

Catalog is created from a raw data ASCII file (bsc5.dat).

__init__(create_from_database=False, filename='bright_star_catalog', min_mag=-12.0, max_mag=3.0)

class ctapointing.catalog.GaiaCatalog(create_from_database=False, filename='gaia_catalog', min_mag=3.0, max_mag=9.0, magnitude_correction=0.25)

Gaia DR2 star catalog. Data to construct the catalog is read from the Gaia server using astroquery.gaia.

__init__(create_from_database=False, filename='gaia_catalog', min_mag=3.0, max_mag=9.0, magnitude_correction=0.25)

ctapointing.catalog.query_catalog(fov_centre, fov_radius, min_mag=-12.0, max_mag=12.0, obstime=None)

Query both bright star and Gaia catalogs for stars in a given magnitude range and within a given (circular) field of view.

A correction of the Gaia magnitude is applied to match that magnitude to the V-magnitude provided by the bright star catalog.

Proper motion is taken into account; the ICRS coordinates of the stars are computed for the given observation time.

Parameters:

• fov_centre (Coordinate) – Sky coordinate of field-of-view centre

• fov_radius (Angle) – Opening angle of the field-of-view

• min_mag (float) – Minimum magnitude. Only stars with mag >= min_mag are considered.

• max_mag (float) – Maximum magnitude. Only stars with mag <= max_mag are considered.

• obstime (astropy.time.Time or None) – Time of observation. This is used to calculate the ICRS position of each star after proper motion correction. Set to ‘None’ for no correction.

Returns:

coords, mag, source-id – Coordinates and magnitudes of all found stars.

Return type:

tuple

Functions

query_catalog(fov_centre, fov_radius[, ...])

Query both bright star and Gaia catalogs for stars in a given magnitude range and within a given (circular) field of view.

Classes

GaiaCatalog([create_from_database, ...])	Gaia DR2 star catalog.
BrightStarCatalog([create_from_database, ...])	Yale Bright Star Catalog.

Class Inheritance Diagram