query_catalog

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