Comet 46P/Wirtanen – Naked Eye this December?

Comet 46P/Wirtanen is getting brighter, and heading northwards.
Now Naked Eye (Apparently!).

Comet 46P taken from home – 13th December 2018.
72mm Altair refractor and Nikon D750 DSLR.

Click this link to download a printable version of the information on this Web page.

This periodic comet is going to reach perihelion, (closest to the Sun), and closest to The Earth (only 7,220,000 miles distant) and at its brightest on the 16th of December.

At this time it is predicted to be around 3rd magnitude and close to the Pleiades Star Cluster. If the prediction turn out to be correct (How often are they?), the comet could easily become an easy naked eye object around this time.

Comet 46P has an orbital period of 5.4 years and the solid nucleus has a diameter of about 1.2 km.

Comet 46P was the original target for the Rosetta and Philae mission.
The target was changed to Comet 67P/Churymov-Gerasimenko when the launch of Rosetta was delayed after the Ariane rocket failure in 1996.

Here are the circumstances of this years apparition.

You can follow progress on the Facebook Page dedicated to the comet:

46P is currently in the constellation of Fornax, low down in the southern sky in the early around midnight. Currently about magnitude 10, it is challenging from the UK, being so far south.

It is currently heading south, but by the second week in November, it then starts heading north. From this point onward, it will start to pick up speed as the distance from the Sun and Earth decreases.

Path of Comet 46P during November and December 2018.
Click on the map for a better view.

By the first week of December, the comet is within the stars of Cetus and now moving even faster northwards, brightening all the time.
The Moon will be New on the 7th, so will be well out of the way at this time.

Path of Comet 46P during December.

The comet moves swiftly into Taurus mid-December and should now be starting to get very bright.

On the 16th of December, at the time of it’s brightest, at magnitude 3(?), it is nestled very nicely between the Hyades and Pleiades star clusters. We hope it will be a nice naked eye object at this time. The Moon will be a day after 1st Quarter at this time, so will be setting well before midnight, so should not disrupt the view once it sets.

Close up view of 46P’s path around Perihelion.

The comet continues to head northwards, into Auriga, passing through the triangular asterism of “The Kids” on the 22nd of December.
The Moon will unfortunately be full at this time, so will tend to wash out the comet.

It passes the first magnitude star Capella on the 23rd and 24th.
The gibbous Moon in the morning sky will now disrupt observations until the second week of December.

The comet’s apparent motion will have started to slow down a bit now and should have started to fade in brightness, but hey, post-perihelion, anything could happen…

By the end of the year, the comets pace has slowed right down and we find it within the constellation of Lynx.

Path of the comet during January and February 2019.

During January, the comet has slowed right down, faded considerably  and now starts a long slow loop as it moves into the head of Ursa Major.

Let’s hope that this comet lives up to all our expectations and gives us a great winter show.






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