simpunch.stars#

Functions for starfield generation.

Attributes#

`THIS_DIR`
`HIPPARCOS_URL`

Functions#

`load_catalog`(, url)	Load the Hipparcos catalog.
`load_raw_hipparcos_catalog`(, url)	Download hipparcos catalog from website.
`filter_for_visible_stars`(→ pandas.DataFrame)	Filter to only include stars brighter than a given magnitude.
`find_catalog_in_image`(, mode)	Convert the RA/DEC catalog into pixel coordinates using the provided WCS.

Module Contents#

simpunch.stars.THIS_DIR#

simpunch.stars.HIPPARCOS_URL = 'https://cdsarc.cds.unistra.fr/ftp/cats/I/239/hip_main.dat'#

simpunch.stars.load_catalog(catalog_path: str = os.path.join(THIS_DIR, 'data/hip_main.dat'), url: str = HIPPARCOS_URL) → pandas.DataFrame[source]#: Load the Hipparcos catalog.

simpunch.stars.load_raw_hipparcos_catalog(catalog_path: str = os.path.join(THIS_DIR, 'data/hip_main.dat'), url: str = HIPPARCOS_URL) → pandas.DataFrame[source]#

Download hipparcos catalog from website.

Parameters:

catalog_path (str) – path to the Hipparcos catalog
url (str) – url to the Hipparcos catalog for retrieval

Returns:

loaded catalog with selected columns

Return type:

pd.DataFrame

simpunch.stars.filter_for_visible_stars(catalog: pandas.DataFrame, dimmest_magnitude: float = 6) → pandas.DataFrame[source]#

Filter to only include stars brighter than a given magnitude.

Parameters:

catalog (pd.DataFrame) – a catalog data frame
dimmest_magnitude (float) – the dimmest magnitude to keep

Returns:

a catalog with stars dimmer than the dimmest_magnitude removed

Return type:

pd.DataFrame

simpunch.stars.find_catalog_in_image(catalog: pandas.DataFrame, wcs: astropy.wcs.WCS, image_shape: int, int, mode: str = 'all') → numpy.ndarray[source]#

Convert the RA/DEC catalog into pixel coordinates using the provided WCS.

Parameters:

catalog (pd.DataFrame) – a catalog dataframe
wcs (WCS) – the world coordinate system of a given image
image_shape ((int, int)) – the shape of the image array associated with the WCS, used to only consider stars with coordinates in image
mode (str) – either “all” or “wcs”, see <https://docs.astropy.org/en/stable/api/astropy.coordinates.SkyCoord.html#astropy.coordinates.SkyCoord.to_pixel>

Returns:

pixel coordinates of stars in catalog that are present in the image

Return type:

np.ndarray