class sbpy.photometry.HG12_Pen16(*args, **kwargs)[source]

Bases: sbpy.photometry.HG12

Revised H, G12 model by Penttil”a et al. (2016)

This system is the revised H, G12 system by Penttil”a et al. (2016, Planet. Space Sci. 123, 117-125) that has a continuous derivative with respect to parameter G12. The original model as adopted by IAU as the “standard” model for disk-integrated phase functions of planetary objects is implemented in class HG12.


>>> # Define the phase function for Themis with
>>> # H = 7.121, G12 = 0.68
>>> import astropy.units as u
>>> from sbpy.calib import solar_fluxd
>>> from sbpy.photometry import HG12_Pen16
>>> themis = HG12_Pen16(7.121 * u.mag, 0.68, radius = 100 * u.km,
...     wfb = 'V')
>>> with solar_fluxd.set({'V': -26.77 * u.mag}):
...     print('geometric albedo = {0:.4f}'.format(themis.geomalb))
...     print('phase integral = {0:.4f}'.format(themis.phaseint))
geometric albedo = 0.0622
phase integral = 0.3804

Initialize DiskIntegratedPhaseFunc

radiusastropy.units.Quantity, optional

Radius of object. Required if conversion between magnitude and reflectance is involved.

wfbQuantity, SpectralElement, string

Wavelengths, frequencies, or bandpasses. Bandpasses may be a filter name (string). Required if conversion between magnitude and reflectance is involved.

**kwargsoptional parameters accepted by


Attributes Summary


Methods Summary

fit_deriv(ph, h, g)

Attributes Documentation

param_names = ('H', 'G12')

Methods Documentation

static fit_deriv(ph, h, g)[source]