draw_stars

simsit.tools.draw_stars(stars, *, t0, exptime, wcs0, tracker, psf, image, nsplit=2)

Draw stars into an image while accounting for tracker motion during exposure.

Parameters

starsastropy.table.Table

Input star table with columns:

  • ra: right ascension in degrees

  • dec: declination in degrees

  • nphot: number of photons to draw

t0astropy.time.Time

Exposure start time.

exptimefloat

Exposure time in seconds.

wcs0galsim.GSFitsWCS

Reference WCS at the start of the exposure.

trackerTracker

Tracker object providing boresight and rotation as a function of time.

psfgalsim.GSObject

Point-spread function model.

imagegalsim.Image

Output image to draw into.

nsplitint, optional

Number of time segments used to approximate motion during the exposure.

Returns

astropy.table.Table

Updated table containing the original star information plus:

  • x, y: image coordinates at exposure midpoint

  • x_FITS, y_FITS: FITS-style pixel coordinates