gaia2romanisimcat

romanisim.gaia.gaia2romanisimcat(gaiacat, date, refepoch=2016.0, boost_parallax=1, fluxfields=['F184'])

Convert Gaia output to a catalog of locations for input to romanisim.

Mostly an astrometry routine, doing the usual parallax and proper motion computations by hand. Caveat emptor—may all be wrong!

boost_parallax is intended to allow accounting for the fact that parallaxes are for 1 AU, but Roman will be at 1.01 AU (L2) and so everything moves by 1% more than you might expect. If one wants to do better than that one needs to think about the detailed orbit of Roman in L2; the location of L2 itselfs moves annually and monthly due to the eccentricity of the Earth’s orbit and the fact that the Earth is not at the Earth-moon barycenter.

Parameters:

gaiacatastropy.table.Table

Gaia catalog, containing at least ra, dec, pmra, pmdec, parallax, phot_g_mean_mag fields

dateastropy.time.Time

Time of observation

refepochfloat

Reference epoch of Gaia parameters

boost_parallaxfloat

Amount to boost parallaxes by (L2 describes a wider orbit than the Earth’s)

fluxfieldslist[str]

List of strings to fill with estimated fluxes

Returns:

catalogastropy.table.Table

astropy Table formatted for input to romanisim