- About PSI
Here we provide the plots showing the heliocentric and geocentric distances, rh and Delta (solid black line and dashed black line, respectively), as well as the solar elongations (blue dashed line) for each comet. The file names are TGK_ephem.pdf, HMP_ephem.pdf, and Wirtanen_ephem.pdf.
We also provide plots showing the "up times" of the comets for different latitudes (at 5 deg intervals and "m" in the file name stands for minus latitudes and "p" stands for positive latitudes). The solid black and blue dashed lines are times that the comet is above 30 deg and 15 deg, respectively. The red and orange dot-dash lines are the total and nuclear magnitudes, as calculated from the coefficients given in JPL Horizons (note that other systems will predict different brightnesses and therefore these magnitudes should be considered as ROUGH estimates; in particular, we like to refer to Seiichi Yoshida's website www.aerith.net and his predictions). An observer should choose the closest latitude to the relevant observatory in order estimate the "up time" for a given comet.
Observing Plots for Comet 41P/TGK
Observing Plots for Comet 45P/HMP
Observing Plots for Comet 46P/Wirtanen