[Outbackmanyep]

Originally Posted by jjjnettie

I viewed Lulin this morning through 12x50 binos and found the comet, as you said, to be smaller and fainter than M4.
The binos were hand held which made it impossible to see it as anything but a shaky fuzzy blob. If the sky is clear tomorrow morning I must point the Gstar at it and see what I can capture.
We've had a drought of astronomical events, nothing really since Comet Holmes, finally something to get excited about!!

Hi Nettie and others,
The comet certainly is a fuzzy blob! My mag estimate from the morning of the 29th was 6.7, other mag estimates have it around 6.5. I tried to see it naked eye but the zodiacal light interferes with trying to make it out. The comet has a small coma dia of around 8', but if you look closely you might notice a bright point of light in the middle which is the "false nucleus", giving the comet a degree of condensation of around 6.
When the comet brightens this point of light becomes larger and more noticable, and the Degree of Condensation will increase, C/2007 P1 McNaught at the time of it's apparition had a DC of 9, which means the comets coma appeared "star-like" without the fuzzy edges noticable.

The way you would compare brightness of the comet is to memorise the apparent brightness of the comet, then de-focus a nearby star to around the same diameter of the comet and compare the brightness of the de-focussed star to the IN-FOCUS comet. Never compare an out of focus star to an out of focus comet. This is called the In-Out or VSS method of measuring a comet's brightness, and should always be made with the smallest instrument as practicable.
When there is a definite stellar-like point in the coma, the method you use is called a "Modified In-Out" method. This is where you would de-focus the comet slightly so that the point of light is smeared out as even in brightness as possible, then memorising the comet image with a suitable out of focus star comparable in brightness.

The 3 basic measurements are : estimated magnitude, estimated diameter of the coma, and the Degree of Condensation.
A DC of 1 will give you a faint uniform coma with no central brightening, a DC of 3 means that a central brightening is noticable. A DC of 6 means the central brightening is star-like, and a DC of 9 means the central brightening is uniform across the entire coma giving the coma a star-like appearance.

Other things to note are a tail (length and position angle from North), or the shape of the coma (Such as a fan like appearance or bar-like such as in the case of N3 Lulin), the time and date of your observation, the number of the comaprison star you use and the catalogue of the comparison star measurement (Such as GSC, Tycho, Hipparcos, ASAS-3 etc) Not all catalogues are recommended, such as USNO magnitudes.
The Central Bureau for Astronomical Telegrams have a link to International Comet Quarterly pages which outline the correct methods and catalogues to use.

Your G-Star should capture N3 Lulin no worries!

Good luck, and here's to a bright comet!