Internal Sun reference spectra#
Although the Sun is not a necessary reference for photometric calculations, we provide observed and theoretical references for the solar spectrum following Colina, Bohlin, & Castelli 1996.
The observed solar spectrum comes from CALSPEC sun_reference_stis_001.fits which provides the ultraviolet to near-infrared absolute flux distribution of the Sun covering the 0.12-2.5 μm wavelength range. The solar reference spectrum combines absolute flux measurements from satellites and from the ground with a model spectrum for the near-infrared.
The theoretical spectrum comes from the Kurucz’93 atlas: sun_kurucz93.fitsftp://ftp.stsci.edu/cdbs/grid/k93models/standards/sun_kurucz93.fits The theoretical spectrum is scaled to match the observed spectrum from 1.5 - 2.5 microns, and then it is used where the observed spectrum ends. The theoretical model of the Sun uses the following parameters when the Sun is at 1 au:
log_Z |
T_eff |
log_g |
V_{Johnson} |
|---|---|---|---|
+0.0 |
5777 |
+4.44 |
-26.75 |
The interface to the Sun templates is given through the pyphot.sun.Sun class.