Comet C/2022 E3 (ZTF) brightening up

I know some of you have been paying attention to the news outlets discussing the arrival of a new, bright comet this February - but let me tell you there is a lot of sensationalism going on as well. Some claiming it to the comet of the century (when have we heard that before), others heralding it's triumphant return since it's last visit to the inner solar system over 50,000 years ago (that part is true - the part about the timing, not necessarily the 'triumphant' part).

But, nevertheless, there is indeed a fairly bright comet, named C/2022 E3, that has just passed it's closest point to the sun and is quickly approaching it's closest point to Earth. It passed the sun on January 12th and on Wed, Feb 1st, it will be closest to us - about 0.28 AU (astronomical units, where 1 AU is the distance from the sun to the earth, or about 93 million miles). As it does so it will continue to get brighter.

Photographs show a striking blue-green coma - a typical feature often seen in comets as they approach and get close to the sun. The intense ultraviolet (UV) light breaks down the large organic molecules present in the comet into the simpler ones, and it's the diatomic carbon (C2) that produces the green glow. Here is an image I was able to capture on January 15th using my WO GT102 APO refractor and ASI533mc camera.

This comet is rather large and you can clearly see the wide dusty fan of a tail and the green coma. There is a very, very faint (not easy to see on this image) ion tail dropping down to the bottom right which extends a considerable distance beyond the field of view. Later this month I plan to image with my wide field WO ZS61 to capture the ion tail.

Currently visible to observers in the Northern Hemisphere, the best time to view C/2022 E3 is in the early morning just a few hours before dawn. The comet's brightness right now is hovering at about magnitude 7, easily visible through binoculars or any small telescope.  In fact, at that magnitude level it is pretty bright thru a good telescope. And if the comet brightens to magnitude 6 or better, C/2022 E3 might be visible to the naked eye under good conditions - and that means a relatively dark sky with clear atmosphere. In the Baltimore/Washington area the light pollution is so high that it probably can't be seen without optical aid, but a decent pair of binoculars should show it well.

Here is a sky map that shows the position of C/2022 E3 as it races through the early morning hours of January 18 to January 27. Positions are for 5:00AM EST. 

After late January the comet moves further west and is well placed for evening viewing, getting higher and higher each day. Here are the positions from January 21 to Feb 4 at 9:00 PM EST.

Although the comet is nearest the earth on Feb 1, the moon (almost directly overhead and approaching full moon on the 5th) will interfere considerably. Sky and Telescope magazine provides this handy chart for the best times to see the comet based on the moon and altitude of the comet.

You can stay abreast of the comet’s magnitude, coma diameter, and more at the Comet Observation Database (COBS). Click on the Recent Observations link, then search for C/2022 E3. Another excellent source is Weekly Information about Bright Comets.