Please note that nearly every comet that is uploaded via the Observable
Comets list for Guide or any other planetarium program has a magnitude base on
orbital parameters and you should not expect every comet to be right on target -
or even close as you are discovering with 45P - to predicted. Many are far
brighter that given in the computed values and others are dimmer.
I suspect that all the incorrect hype over the media last week was due
principally to just this fact - the comet's magnitude predicted by ephemeris
elements and not the actual values that are being reported.
In my opinion this is a good thing, because it would give observers an
improper bias toward magnitude estimates. There are in fact a couple of
individuals who are reporting magnitudes to MPC that appear to be right off of
the lists and not actual computed or observed magnitudes. Always report
what you see and assume that the data is subject to considerable error.
Roger, I know that you are aware of this, but I am stating the above for
the sake of those confused by the numbers.
------------
Dr. Clay
----- Original Message -----
Sent: Sunday, February 12, 2017 3:13
PM
Subject: RE: [guide-user] RE: comet 45P
-- whats going on ?
Oops,
sorry, I thought I’d updated my comet info but I hadn’t. Now, after I
have done that, guess what I get? Yes, 3.7!
Cheers,
Roger
well it's not 3.7 so i wonder How 2 of us get the
wron result ?
roger --did you use update from MPC ?
thx,
bob