Now that the Moon is out of the early evening sky, far northern observers are out in force hunting down Comet C/2009 Yi-SWAN… and it’s there! In 10X50 binoculars it appears like a very faint, small globular cluster, but definitely has the signature of a comet in a 4.5″ telescope. Surprisingly enough, it’s not very hard to find. Would you like a hand?
First use the rough locator chart that I’ve provided for you at the beginning of this article to get you in the right area. Don’t forget that Cassiopeia is circumpolar and you will need to orient the map according to its position at the time you view it. Rather than confuse you further – just remember as the days pass that Yi-SWAN’s trajectory will take it slowly towards the left hand side of the chart. Here is a close up look at where it will appear in a magnitude 8 filtered field of stars on the night of April 15.
At this point I personally have not observed any tail, nor has any of my co-observers. By using the de-focusing method, we estimate the Comet Yi-SWAN to be right at its 8.5 magnitude mark, totally diffuse and no sign of a bright nucleus at this time. We’d be interested in hearing your observations, too!
Best of luck…