Comet 46P Wirtanen is a small short-period comet with a current orbital period of 5.4 years.
It was the original target for close investigation by the 
Rosetta spacecraft, planned by the European Space Agency,
but an inability to meet the 
launch window caused Rosetta to be sent to 67P/Churyumov–Gerasimenko instead.
It belongs to the 
Jupiter family of comets, all of which have aphelia between 5 and 6 AU. Its diameter is estimated at 1.2 kilometres (0.75 mi).


46P/Wirtanen was discovered photographically on January 17, 1948, by the American astronomer Carl A. Wirtanen.
The plate was exposed on January 15 during a stellar proper motion survey for the 
Lick Observatory.
Due to a limited number of initial observations, it took more than a year to recognize this object as a short-period comet.


On 16 December 2018 the comet passed 0.0774 AU (11,580,000 km; 7,190,000 mi) (≈30.1 LD) from Earth,
reaching an estimated magnitude of 4.2,
 making this pass the brightest one predicted, and the brightest close approach for the next 20 years.
Its magnitude could peak as bright as magnitude 3 near its December 16, 2018 closest approach.


The 2018 close approach, combined with Wirtanen's brightness provides an opportunity to study a potential future spacecraft mission target in detail.
A worldwide observing campaign
has been organized to capitalize on the favorable circumstances of this apparition.



Here's the GREAT 2018 CHRISTMAS COMET!!!
Shot Prime Focus. Orion EON (500mm f/6.25) ED80 & Canon 60Da Astrocamera w/ MPCC Field Flattener.

M45-46P-12-20-2018


M45, the Pleiades and the Hyades photobombing Comet 46P/Wirtanen at its closest approach to Earth on December 17th, 2018.
Shot at my Shiloh Observatory in Statesville NC, USA.
Canon 60Da w/35mm lens piggybacked on the Losmandy Titan.
32 x 30 second exposures at 1600 ISO.

The comet was pretty low to the horizon when I shot this image and difficult to spot with the naked eye,
but still easily spotted in 10x70 binoculars.
By the time it reached zenith it was easily discernible as a lunar sided fuzzy, gray disk of nebulosity.



46P_Wirtanen_60Da_300mm

 10 x one minute exposures for still image.



It was 36 cold degrees out there with thin cirrus popping up at random. You can see the cirrus in the animation as bright flashes.

Here's a couple of quick processes of my Comet 46P/Wirtanen images from December 13th, 2018.. All are singles, no stacking yet. Canon 60Da
35mm
Canon 60Da Astrocamera with 35mm lens.


    80mm
Canon 60Da Astrocamera with 80mm lens.

  
300mm
Canon 60Da Astrocamera with 200mm lens.


ED80   
Orion EON ED80 w/Canon 40D @ prime focus.



2018-12-11_00_34_20Z_OJWA_46P-Wirtanen
   Explore Scientific 152mm w ZWO ASI 174mm @ prime focus.




The rumor on the streets of the North Pole says that Rudolph took a sick day, so COMET had to lead the sleigh last Christmas... and I have photographic PROOF!!!
Merry Christmas Comet Wirtanen



Short animations I made of Comet Wirtanen from subs.           
46P-Christmas_2018_Comet A  2018-12-03_46P-Wirtanen Startrails   Startrails15Startrails30.avi