Here is last
nights shooting of the comet, still in a very rich part of Cepheus.
Now beaming at magnitude 7, the comet has a very faint gas tail,
and a broad short dust tail.
methods are shown here, all with the same 60 minutes of data
using 2 minute sub frames. The first is stacking the comet and
the stars in one hour show the movement of the comet during that
interval. A very rich star field indeed!
The second method
is to combine the median stacked image with the star stacked
image, after subtracting out the trailed comet. It is a realistic
portrait of where the comet was on the first shot in the sequence.
The final third
shot is a median combined image, showing the very faint tails
at the expense of the stars.