Hi Bernd,

Guide has no brightness data for this object. I don't even have
astrometry for it (which is odd; it ought to be in the MPC's astrometry
data for comets). I had hopes that I might be able to dig up data with
magnitude estimates, but that doesn't seem likely.

Guide has one misbehavior and one bug here. The "misbehavior" is
reporting "mag 99.0" instead of "no magnitude available", and I've
just fixed this.

The "bug" involves how it shows comets without magnitude parameters.
The head and tail size are determined using formulae kindly supplied by
Andreas Kammerer, as described at

http://www.projectpluto.com/update7b.htm#comet_tail

When there are no mag parameters, I've been feeding Andreas' formula
an absolute magnitude of zero, meaning a _very big_ comet. The next
update I post will use an absolute magnitude of 10 in such cases, i.e.,
a pretty faint comet. That way, you will still see a tail, and its
position angle will be meaningful, but it won't be an unrealistically
huge head and tail such as you are seeing now. (And when you click on
the object, you'll see "No magnitude available", so you will know not
to trust the tail length and head size very much anyway.)

-- Bill