Comet 46P/Wirtanen
This comet comes close to Earth in its 2018 apparition towards the end of the year. It may therefore become quite bright. For this reason I have generated the following charts to help follow it. In December the comet is moving rapidly northwards and in the middle of the month it is likely to be at its closest to Earth and with its brightest apparent magnitude.
Perihelion is on 12th December at 1.05au. Perigee is on 17th December at 0.08au.
Pointing to stars or date-labelled comet positions on each chart will show ephemeris data. The date-labelled positions are for 0h UT on those dates.
Sample star data
Star identifier, from Hipparchos/Tycho data
Visual magnitude, V
(variable stars are indicated)
Colour index, B - V
Sample comet data
Julian day, JD
Right Ascension
Declination
Distance from Sun, r
Distance from Earth, Δ
Angle from Sun, elong
Estimated magnitude, V
Stars shown in green squares have similar colour index to the Sun and so could be useful for magnitude comparisons.
NB: The magnitude could turn out to be very different from the estimate