SkyTools 3: Software for Comet Observing

In late 2008 comet observers around the world turned their telescopes to view the bright comet 85P/Boethin only to see nothing. Unknown to them, this comet had apparently disintegrated and was no longer detectable. Every software product except SkyTools continued to show this comet as an easy object for small telescopes for weeks and even months after it was known to have disappeared.

Why? Because all software products obtain their comet data directly from the IAU, which is fine for generating precise positions. But the magnitude parameters published with these positions are often out of date or in error. In the ever-changing world of comet observing, knowing the current size and magnitude of a comet is essential. This information can only be obtained from recent observations and SkyTools is the only software that integrates these recent observations into its easily accessible online database.

Is that Comet Visible in My Telescope?

What makes visual comet observing frustrating is that the big diffuse comets are far more difficult to detect than the small compact ones. Even with an accurate magnitude it is difficult to know if a given comet will be visible to you. SkyTools uses a sophisticated algorithm to take the guesswork out of comet observing. It predicts how difficult it will be to detect a comet under your conditions with your telescope/binoculars. And it accurately depicts the comet's diameter, giving you a clear idea of what to look for in the eyepiece.

When and Where Should I Look?

The SkyTools planning tools really shine for comets. Quickly find out which nights are best to observe your comet, what time you should go out, and either create a custom finder chart or drive your computer controlled scope right to it.

Custom Observing Synopses

Imagine a program that could tell you, in words, everything you need to know about observing a comet:

On this night C/2007 N3 (Lulin) is best visible between 06:52p and 12:43a, with the optimum view at 08:44p. Look for it in Cancer, high in the sky in moonlight. It is easy visually in the Orion StarBlast 4.5. Use the Explorer II 17mm for optimum visual detection. It is magnitude 6 with a diameter of 14.0'.

In the following 30 days this object is obvious visually on March 13-27, with the best view coming on March 13. During this period it will fade rapidly and will reach peak altitude of 71° on March 16.

C/2007 N3 (Lulin) is past perihelion, which occurred in early January 2009. In late February this comet passed within 0.4 AU of the earth. It also reached maximum brightness of magnitude 4.5 in late February. The best visibility from Tuscon near maximum brightness was predicted to be in late February when it was approximately magnitude 4.5. On February 24 this comet was moving quickly across the sky at a peak rate of 12.9 "/min.

Finding Comets

With the aid of the multi-view telescope (or binocular) finder charts it is a simple matter even for a beginner to find a telescope or binocular comet. The charts are true simulations that display what you will see in the eyepiece at your location with your instrument. Everything from light pollution to the experience of the observer is taken into account. Click on the thumbnail to see a plot of comet Ikeya-Zhang as seen in 8x56 binoculars from a dark site. The comet is plotted every night at the time when it is best observed. The printed finder charts are similar, although usually black on white for ease of use at the telescope.

Logging Your Observations

Once you have made your observation the SkyTools logbook provides an ideal means of recording what you saw. Use the Night Log to record the entirety of the observing experience, such as that time when those Raccoons nearly scared you into dropping your Nagler!