Atlas module

Atlas class

Creation of the star maps based on user parameters.

class Atlas.Atlas(latitude, ybp_min, step_size, ybp_max, mag_limit, neighbours)

Bases: object

The Atlas handles all common parameteres that are the same for a set of star maps, such as observer position, mag limit, and so on.

Parameters

  • latitude (int) – Northern latitude of the observer. Southern currently not supported.

  • ybp_min (int) – Minimum years before present for which a map should be calculated.

  • step_size (int) – Step size in years between star maps

  • ybp_max (int) – Maximum years before present for which a map should be calculated.

  • mag_limit (float) –

    Dimmest brightness of stars added to the map.

    Note

    Smaller values correspond to higher brightness.

  • neighbours (int) – Number of neighbouring stars for which calculations should be performed.

__init__(latitude, ybp_min, step_size, ybp_max, mag_limit, neighbours)

Initialize self. See help(type(self)) for accurate signature.

createAtlas()

Creates the collection of maps based on the time span selected.

save()

Saving the star maps

Creates save files with naming scheme based on their parameters.

class Atlas.Map(ybp, parent)

Bases: Atlas.Atlas

__init__(ybp, parent)

Individual star map

Inherits most necessary parameters from Atlas.

Parameters

ypb (int) – Years before present for which star map should be calculated.

calculate_angular_distance(active_entry, target_entry)

Function to calculate angular distance between stars

Parameters

  • active_entry (int) – The star from which the angular distance is measured.

  • target_entry (int) – The star to which the angular distance is measured.

calculate_new_coordinates(ra, de, pm_ra, pm_de, ybp)

Calculates new positions of stars from their proper motions

Parameters

  • ra (float) – Current right ascension of the star.

  • de (float) – Current declination of the star.

  • pm_ra (float) – Current right ascension element of the star’s proper motion.

  • pm_de (float) – Current declination element of the star’s proper motion.

  • ybp (int) – Years before present

chop(line)

Splits input lines at separator

Foreign function. Splits lines of the HIP-star-catalogue along seperator.

createMap()

Creates map, returning a nested dictionary of distance and angle values of each star to a number of neighbours, selected by the user.