Two sketches of 46P/Wirtanen creating one gif showing the comets movement over time. 20:40 UT Dec 9th 2018 & 00:50 UT Dec 10th 2018. Dob, 1,200 mm FL / 32 mm eyepiece/ 37X/ pastel and gel pen. 4.5 mag, DC 4 coma visible naked eye , huge diffuse object.
While viewing I thought I observed some radial features but not clear enough to include in the sketches. The edges / shape of the coma was difficult to see. No green observed or tail visible to me at the time.
This is a view from my dob therefore south is at the top. The comet is acutally heading upwards in the nightsky. It is remarkable how quickly it is moving away from the star 94 Cet in my drawings.
This comet has a coma of circa 36,000 km. The nucleus is spewing out gas and dust. To my eye it had no green tint. Only comet C/2014 Q2 Lovejoy in 2015 gave me that delight.
In-between haze and misty rain with some clear patches, this enormous comet and my eye met several times. However to do a drawing a good steady view is required.
I prepared several drawing circles as the forecast offered a few hours of clear sky. However in reality the evening did not play out as expected. . My plan was to draw the comet at least four times as it moved through the nightsky. This comet is moving very fast. A few more sketches would have made the animation smoother. As the evening played out I only had the opportunity to draw 46P/ Wirtanen twice.
Even though it has echo’s of comet 17P/Holmes it is however not as yet as well difined. Its central condenseation is dull not stellar. It’s coma is enormous but not as thinly spread or round to the eye as Holmes. Sometimes while observing I thought I saw variations in the density of the coma but not at all clearly enough to include.
Viewing prospects
Comets are very exciting and this unique object may get brighter as it moves higher in the sky. On December 16th the comet will be to the left of M45 (The Pleiades) in the days before that it will be charging up between the Hyades and M45. The comet is entering a visually rich area of the night sky . However as the forecast here in Ireland is for cloud. I am not very hopfull of catching another view.
I feel lucky to have seen it that night from Louisburgh, Co Mayo Ireland. A dismal December weather pattern will terminate my viewing prospects. But one can only be hopful 🙂
Find Comet 46P/Wirtanen for your self
The Sky Live Wirtanen Page to help you find it.