As mentioned in the last news item, the SWAN instrument on-board SOHO recently discovered it eighth comet. The good news is that this comet will definitely be crossing both LASCO C3 and C2! Unfortunately, the comet is remaining relatively faint (about mag 9 as of late-July, 2006), and will not reach perihelion (closest approach to the Sun) until a few weeks after it has left the LASCO field of view, so we are quite confident that this will not be a sensational comet transit. However, even at its current brightness it should show up in the images.
So, where and when will it appear? Well, the below images show the approximate path of the comet through our images. (Note that subsequent alterations to the current orbit, could change these times by as much as a few hours and the positions by as much as a few pixels.)
Track of the comet C/2006 M4 (SWAN) through LASCO C2
Unfortunately, the SWAN comet is perfectly timed to coincide with the SOHO keyhole. For those of you who are not familiar with these, it means that for the majority of the time that the comet is in the LASCO field of view, we will be suffering from poor quality data (lots of missing blocks from the images), large data gaps (several hours or more of unrecoverable data), and closed instrument doors (no images at all!). The impact of this upcoming keyhole is yet to be know, but right now it is not looking good for observing the comet in all of C2 and the last two weeks in C3… More information on this will be posted as I receive it.